National 5 Physics

Dynamics

Revision Dynamics A/B Test

Vectors

V-T Graphs Acceleration

Newton’s Laws Conservation of Energy

Projectile Motion

Vectors Multiple Choice Questions Q1. Which of the following quantities is fully described by its magnitude?

A Force B Displacement C Energy D Velocity E Acceleration

Q2. Which of the following contains two vectors and one scalar quantity?

A Acceleration, mass, displacement B Displacement, force, velocity C Time, distance, force D Displacement, velocity, acceleration E Speed, velocity, distance

Q3. A vehicle follows a course from R to T as shown.

The total journey takes 1 hour. Which row in the table gives the average speed and the average velocity of the vehicle for the whole journey?

Average speed Average velocity

A 2∙6 kmh−1 (023) 3∙4 kmh−1

B 2∙6 kmh−1 3∙4 kmh−1 (203)

C 3∙4 kmh−1 (203) 2∙6 kmh−1

D 3∙4 kmh−1 2∙6 kmh−1 (023)

E 3∙4 kmh−1 2∙6 kmh−1 (203)

North

2·4 km

1.0 km T S

R

Q4. Which row contain two scalar quantities and one vector quantity?

A Distance, displacement, velocity B Speed, mass, displacement C Distance, weight, force D Speed, weight, displacement E Velocity, force, mass

Q5. A student follows the route shown in the diagram and arrives back at the

starting point.

Which row in the table shows the total distance walked and the magnitude of the final displacement?

Total Distance (m) Final Displacement (m)

A 0 80

B 0 380

C 190 0

D 380 0

E 380 380

150m

150m

40m 40m

The student starts and finishes here

Q6. An object moves 24m North then 38m east. The size of the resultant displacement is

A 14m B 24m C 38m D 45m E 62m.

Q7. At an airport an aircraft moves from

the terminal building to the end of the runway.

Which row shows the total distance travelled and the size of the displacement of the aircraft?

Total distance travelled (m)

Size of displacement (m)

A 400 800

B 450 200

C 450 400

D 800 400

E 800 800

200 m

150 m

250 m

200 m

Runway

Terminal building

38m

24m

North

Q8. During training an athlete sprints 30m East and then 40 m west. Which row

shows the distance travelled and the displacement from the starting point? Q9. Which of the following is a scalar quantity?

A Force B Acceleration C Displacement D Velocity E Energy

Q10. A cross country runner travels 2.1 km North then 1.5 km east. The total time

taken is 20 minutes. The average speed of the runner is A 0.18ms-1 B 2.2ms-1 C 3.0ms-1 D 130ms-1 E 180ms-1

Distance travelled

Displacement

A 10 m 10 m East

B 10 m 10 m West

C 10 m 70 m East

D 70 m 10 m West

E 70 m 10 m East

Q11. Two forces act on an object as shown.

The resultant force acting on the object is A 50 N at a bearing of 053

B 50 N at a bearing of 143

C 50 N at a bearing of 217

D 50 N at a bearing of 233

E 50 N at a bearing of 323.

Q12. Which of the following is a scalar quantity?

A velocity

B displacement

C acceleration

D force

E speed

North

Not to scale

30 N

40 N

Q13. A security guard starts at the corner of a warehouse, walks round the

warehouse as shown and arrives back at the same corner.

Which row in the table shows the total distance walked by the security guard and the magnitude of the displacement of the security guard from the start to the end of the walk?

Total distance (m) Displacement (m)

A 0 0

B 0 340

C 170 130

D 340 0

E 340 340

120m

Warehouse

120m

50m 50m

Security guard starts here

Vectors Extended Response Questions Q1. A student walks around a building from point X to point Y. a. By scale diagram, or otherwise, determine: i. the magnitude of the displacement of the student from point X to point Y; (2) ii. the direction of displacement of the student from point X to point Y. (2) b. The student takes 68s to travel from point X to point Y. i. Determine the average velocity of the student from point X to point Y. (3) ii. The student states that their average speed between point X and point Y

is greater than the magnitude of their average velocity between point X and point Y.

Explain why the student is correct. (2)

75m

X

Y

Building 54 m

14m

North

Not to scale

Q2. A passenger aircraft is flying horizontally.

At one point during the flight

the aircraft engines produce an unbalanced force of 184kN due south (180). At this point the aircraft also experiences a crosswind. The force of the crosswind on the aircraft is 138kN due east (090).

By scale diagram, or

otherwise, determine: a. the magnitude of the resultant force acting on the aircraft. (2) b. the direction of the resultant force acting on the aircraft. (2)

138kN

184kN

not to scale North

V-T Graphs Multiple Choice Question Q1. A ball moves along a horizontal frictionless surface and down a slope

as shown. Ball

Which of the following graphs shows how the speed of the ball varies with time as it travels from P to Q?

P

Q

Speed

Time 0

A Speed

Time 0

B

Speed

time 0

C Speed

Time 0

D

Speed

Time 0

E

Q2. The graph shows how the velocity of a ball changes with time.

The acceleration of the ball is A –8ms-2 B –1ms-2 C 1ms-2 D 8ms-2 E 24ms-2.

Q3. The graph shows how the

velocity of an object varies with time. Which row in the table shows the displacement after 4s and the acceleration of the object during the first 4s?

Displacement (m)

Acceleration (ms-2)

A 10 1.25

B 10 -1.25

C -10 0.8

D 5 -0.8

E -5 -1.25

Time (s)

Velocity (ms-1)

Time (s)

Q4. The graph shows how the velocity 𝑣 of an object varies with time t.

The graph could represent the motion of A a ball falling freely downwards B a rocket accelerating upwards C a ball thrown into the air then falling back to Earth D a ball falling to Earth from rest then rebounding upwards again E a car slowing to a halt then accelerating in the same direction.

t

v

0

V-T Graphs Extended Response Questions Q1. An air descender is a machine that controls the rate at which a climber

drops from a platform at the top of a climbing wall. A climber, attached to the air descender by a rope, steps off the platform and drops towards the ground and lands safely.

The graph shows how the vertical velocity of the climber varies with time from the instant the climber leaves the platform until landing. a. Calculate the acceleration of

the climber during the first 1·4 s of the drop. (3)

b. Calculate the distance the

climber drops during the first 3·0 s. (3)

Air descender Air descender

Time (s)

Q1c. During part of the drop the forces on the climber are balanced. On the diagram show all the forces acting vertically on the climber during this part of the drop. You must name these forces and show their directions. (3)

Q2. A student draws the following graph of the speed of a trolley against

time.

a.i. Describe the motion of vehicle X between points S and T. (1) ii. Describe the motion of vehicle X between points T and U (1) c. Calculate the acceleration between points S and T (3) b. Calculate the distance travelled by vehicle X between points S and T. (3)

Q3. A car of mass 700 kg travels along a motorway at a constant speed. The driver sees a traffic hold-up ahead and performs an emergency stop. A graph of the car’s motion is shown; from the moment the driver sees the hold-up.

a. Describe the motion of the car between A and B. (1) b. Calculate the distance travelled between B and C. (3) c. The driver’s inertial reel seat belt locks when the magnitude of

acceleration is greater than 11ms-2. Does the seat belt lock? Justify your answer with a calculation. (4)

0 0·5 1·0 1·5 2·0 2·5 3·0 Time (s)

30

Speed (ms-1)

0

A B

C

Acceleration Multiple Choice Questions Q1. The table shows the velocities of three objects X, Y and Z over a period of

3 seconds. Each object is moving in a straight line.

Time (s) 0 1 2 3

Velocity of X (m s−1) 2 4 6 8

Velocity of Y (m s−1) 0 1 2 3

Velocity of Z (m s−1) 0 2 5 9

Which of the following statements is/are correct? I X moves with constant velocity. II Y moves with constant acceleration. III Z moves with constant acceleration.

A I only B II only C I and II only D I and III only E II and III only

Q2. A car accelerates from 4.0ms-1 to 20.0ms-1 in 5.0s. The acceleration of the car is

A 0.5ms-2 B 3.2ms-2

C 4.0ms-2 D 4.8ms-2 E 16ms-2

Q3. Catapults are used by anglers to project fish bait into water. A technician designs a catapult for this use.

Pieces of elastic of different thickness are used to provide a force on the ball. Each piece of elastic is the same length. The amount of stretch given to each elastic is the same each time. The force exerted on the ball increases as the thickness of the elastic increases. Which row in the table shows the combination of the thickness of elastic and mass of ball that produces the greatest acceleration?

Thickness of elastic (mm)

Mass of ball (kg)

A 5 0∙01

B 10 0∙01

C 10 0∙02

D 15 0∙01

E 15 0∙02

Q4. A car travels with an initial speed of 10ms-1. It now accelerates steadily

to 30ms-1 in 5s. Which row shows the car’s acceleration and average speed during this time?

Acceleration (ms-2) Average Speed (ms-1)

A 2 10

B 2 20

C 4 20

D 4 30

E 8 30

ball of fish bait

elastic

Q5. A trolley is released from rest at point X and moves with constant acceleration on a slope as shown.

The computer displays the acceleration and average velocity of the trolley between the light gates. The trolley is now released from rest at point Y. Which row in the table shows how the acceleration and average velocity compare with the previous results obtained?

Acceleration Average Velocity

A Less Same

B Same Same

C Greater Greater

D Less Less

E Same Less

Acceleration Extended Response Questions Q1. A student is measuring the

acceleration of a trolley down a slope. She sets up the equipment as shown in the diagram. The trolley is allowed to roll from rest at P.

The following measurements are recorded. Distance from P to Q = 1·0m Length of card on trolley = 0·04m Time taken for trolley to travel from P to Q = 2·5s Time taken for card to pass through light gate = 0·05s

a. Calculate the speed of the trolley at Q. (3) b. Calculate the average acceleration of the trolley. (3)

Q2. A child sledges down a hill. The sledge and child are released from rest at point A. They reach a speed of 3ms-1 at point B. The sledge and child take 5s to reach point B. Calculate the acceleration of the child and sledge.

Q3. A cyclist rides along a road.

The cyclist approaches traffic lights at a speed of 8.0ms-1. He sees the traffic lights turn red and 3.0s later he applies the brakes. He comes to rest in a further 2.5s. Calculate the acceleration of the cyclist whilst braking. (3)

B

C

Q4. Two students are investigating the acceleration of a trolley down a ramp. The first student uses the apparatus shown to determine the

acceleration of the trolley.

Some of the measurements made by the student are shown.

Time for the card to pass through light gate Y 0.098 s

Distance between light gate X and light gate Y 0.22 m

Length of the card 0.045 m

Time for trolley to pass between light gate X and light gate Y 0.56 s

The student determines the instantaneous speed of the trolley at light gate X to be 0.32ms−1.

a. State the additional measurement made by the student to determine the instantaneous speed of the trolley at light gate X. (1)

b. Show that the instantaneous speed of the trolley at light gate Y is

0.46ms-1. (2) c. Determine the acceleration of the trolley down the ramp. (3)

Card

Not to scale

ramp

stop-clock

Electronic timer

Electronic timer

light gate Y

light gate X

ruler trolley

Newton’s Laws Multiple Choice Questions Q1. A rocket is taking off from the surface of the Earth. The rocket engines

exert a force on the exhaust gases. Which of the following is the reaction to this force? A The force of the Earth on the exhaust gases. B The force of the Earth on the rocket engines. C The force of the rocket engines on the Earth. D The force of the exhaust gases on the Earth. E The force of the exhaust gases on the rocket engines.

Q2. A person sits on a chair which rests on the Earth. The person exerts a downward force on the chair. Which of the following is the reaction to this force?

A The force of the chair on the person B The force of the person on the chair C The force of the Earth on the person D The force of the chair on the Earth

E The force of the person on the Earth Q3. A block is pulled across a horizontal surface as shown.

The mass of the block is 5kg. The block is travelling at a constant speed. The force of friction acting on the block is A 0N B 4N C 15N D 20N E 25N

5Kg 20N

Q4. The diagram shows the horizontal forces acting on a box.

The box accelerates at 1∙6 ms-2. The mass of the box is

A 0∙10 kg

B 10∙0 kg C 15∙0 kg D 25∙6 kg E 38∙4 kg. Q5. An unbalanced force of one newton will make a

A 0.1 kg mass accelerate at 1ms-2 B 1 kg mass accelerate at 1ms-2 C 1 kg mass accelerate at 10ms-2 D 0.1 kg mass move at a constant speed of 1ms-1 E 1 kg mass move at a constant speed of 10ms-1.

Q6. An aircraft engine exerts a force on the air. Which of the following completes the ‘Newton pair’ of forces? A The force of the air on the aircraft engine B The force of friction between the aircraft engine and the air C The force of friction between the aircraft and the aircraft engine D The force of the Earth on the aircraft engine E The force of the aircraft engine on the Earth

20N 4.0N

Q7. A space vehicle of mass 120kg is falling vertically towards a planet. The gravitational field strength at this point is 3.5Nkg-1. The vehicle fires a rocket engine which applies a steady upward force of 660N to the vehicle.

Initially the vehicle will A move towards the surface accelerating.

B move towards the surface at a steady speed. C move towards the surface decelerating. D move away from the surface accelerating. E move away from the surface at steady speed. Q8. A rocket accelerates vertically upwards from the surface of the Earth.

An identical rocket accelerates vertically upwards from the surface of Mars. The engine thrust from each rocket is the same. Which row in the table shows how the weight of the rocket and the unbalanced force acting on the rocket compares on Mars and Earth?

Weight on Mars compared to weight on Earth

Unbalanced force on Mars compared to the unbalanced force on Earth

A Greater Greater

B Same Same

C Same Less

D Less Greater

E Less Less

Q9. Far out in space, the rocket engine of a space probe is switched on for a

short time causing it to accelerate. When the engine is then switched off, the probe will A slow down until it stops B follow a curved path C continue to accelerate D move at a constant speed E change direction.

Vehicle

Rocket Engine

Newton’s Laws Extended Response Questions Q1. A plane of mass 750 kg is at rest on a

runway. The engine applies a force of 4·50kN.

a. Calculate the magnitude of the

acceleration of the plane assuming there are no other forces acting on the plane at this point. (3)

b. The required speed for take-off is 54ms-1.

Calculate the time it takes to reach this speed assuming the acceleration is constant. (3)

c. In practice the acceleration is not constant. Give a reason for this. (1) Q2. A spacecraft travels through space between planet X and planet Y.

Information of these planets is shown in the table below. The spacecraft has total mass of 2.5 × 106kg. The spacecraft engines produce a total force of 3.8 × 107N a. The spacecraft is initially on planet X. i. Calculate the weight of the spacecraft when it is on the surface of planet

X. (3) ii. Sketch a diagram showing the forces acting on the spacecraft just as it

lifts off from planet X. You must name these forces and show their directions. (2)

iii. Calculate the acceleration of the spacecraft as it lifts of from planet X.

Planet X Planet Y

Gravitational field strength on surface 8.4Nkg-1 10.4Nkg-1

Surface temperature 17.0°C 9.0°C

Atmosphere No Yes

Period of rotation 48 hours 17 hours

b. On another occasion, the spacecraft lifts off from planet Y. The mass and engine force of the spacecraft are the same as before. Is the acceleration as in lifts of from planet Y less than, more than or equal to the acceleration as it lifts of from planet X?

You must give a reason for your answer using the information contained in the table above. (2)

Conservation of Energy Multiply Choice Q1. A car of mass 1200kg is travelling along a straight level road at a constant

speed of 20ms−1. The driving force on the car is 2500 N. The frictional force on the car is 2500 N.

The work done moving the car between point X and point Y is

A 0 J B 11 800 J C 125 000 J D 240 000 J E 250 000 J.

Q2. A force of 10 N acts on an object for 2.0 s. During this time the object

moves a distance of 3.0 m. The work done on the object is A 6·7 J B 15 J C 20 J D 30 J E 60 J.

20ms−1

50 m

Q3. A motor is used to apply a force of 120 N to a box of mass 30 kg.

The box moves at a constant speed across a horizontal surface. The box moves a distance of 25m in a time of 5.0s. Which row in the table shows the work done on the box and the minimum output power of the motor?

Work done

(J) Minimum output power (W)

A 600 120

B 600 3000

C 3000 600

D 3000 15 000

E 3600 720

Box Motor 120N

Q4. A ball of mass 0∙50 kg is released from a height of 1∙00 m and falls towards the floor.

Which row in the table shows the gravitational potential energy and the kinetic energy of the ball when it is at a height of 0∙25 m from the floor?

Gravitational potential energy

(J) Kinetic energy (J)

A 0∙12 0∙12

B 1∙2 1∙2

C 1∙2 3∙7

D 3∙7 1∙2

E 4∙9 1∙2

Q5. A car driving at 30ms-1 on a level road. It brakes until it is stationary.

Which row gives the energy change of the car?

Energy Change

A Kinetic to Kinetic

B Potential to sound

C Friction to heat

D Kinetic to heat

E Kinetic to friction

0·25m

1·00m

floor

Q6. A man of mass 80kg dives from a diving board which is 10m above water. Neglecting air friction the kinetic energy of the diver immediately before he hits the water is

A 14J B 800J C 1200J D 3900J E 7800J Q7. A ball is released from rest and allowed to roll down a curved track as

shown.

The mass of the ball is 0.50kg. The maximum height reached on the opposite side of the track is 0.20m lower that the height of the starting point. The amount of energy lost is A 0.080J B 0.01J C 0.98J D 2.9J E 3.9J

start

track

0·20m 0·80m

Q8. A cyclist is travelling along a straight road. The graph shows how the velocity of the cyclist varies with time.

The kinetic energy of the cyclist is greatest at A P B Q C R D S E T

R

T

P

Q S

Velocity

Time

Conservation of Energy Extended Response Questions Q1. In a garage, a mechanic lifts an

engine from a car using a pulley system. The mechanic pulls 4.5m of chain with a constant force of 250N. Calculate the work done by the mechanic. (3)

Q2. One type of exercise machine is shown.

A person using this machine pedals against friction forces applied to the wheel by the brake. A friction force of 300N is applied at the edge of the wheel, which has a circumference of 1.5m. How much work is done by friction in one turn of the wheel? (3)

Q3. A ski lift with a gondola of mass 2000kg travels to a height of 540m from the base station to a station at the top of the mountain.

a. Calculate the gain in gravitational potential energy of the gondola. (3) b. During the journey, the kinetic energy of the gondola is 64 000J. Calculate the speed of the gondola. (3)

Q4. A child sledges down a hill from point A to point B. The sledge and

child have a combined mass of 40 kg.

a. Calculate the gravitational potential energy of the child and sledge at

point A. (3) b. Find the kinetic energy of the child and sledge at point B. (1) c. Calculate the speed of the child at point B. (3)

Base station

Q5. During a BMX competition, a cyclist freewheels down a slope and up a ‘kicker’ to complete a vertical jump.

The cyclist and bike have a combined mass of 75 kg. At point X the cyclist and bike have a speed of 8.0ms−1.

a. Calculate the kinetic energy of the

cyclist and bike at point X. (3) b.i. Calculate the maximum height of the jump above point X. (3) ii. Explain why the actual height of the jump above point X would be less than the height calculated in b.i. (1)

Projectiles Multiple Choice Questions Q1. A ball is projected horizontally with

a velocity of 1·5 m s−1 from a cliff as shown.

The ball hits the ground 1·2s after it leaves the cliff. The effects of air resistance are negligible. Which row in the table shows the horizontal velocity and vertical velocity of the ball just before it hits the ground?

Horizontal velocity (ms−1)

Vertical velocity (ms−1)

A 12 12

B 12 1·5

C 1·5 12

D 1·5 13

E 0 12

1·5 m s−1

Q2. A package falls vertically from a helicopter. After some time the package reaches its terminal velocity. A group of students make the following statements about the package when it reaches its terminal velocity.

I The weight of the package is less than the air resistance acting on

the package. II The forces acting on the package are balanced. III The package is accelerating towards the ground at 9·8 m s−2. Which of these statements is/are correct? A I only B II only C III only D I and III only E II and III only

Q3. A ball is released from point Q on a curved rail, leaves the rail horizontally at R and lands 1 s later. The ball is now released from point P. Which row describes the motion of the ball after leaving the rail?

Time to land after leaving rail

Distance from S to landing point

A 1 s less than 2 m

B less than 1 s more than 2 m

C 1 s more than 2 m

D less than 1 s 2 m

E more than 1 s more than 2 m

P

Q

R

S 2m

Not to scale

Q4. Two identical balls X and Y are projected horizontally from the edge of a cliff. The path taken by each ball is shown.

A student makes the following statements about the motion of the two balls.

I They take the same time to reach sea level. II They have the same vertical acceleration. III They have the same horizontal velocity.

Which of these statements is/are correct?

A I only B II only

C I and II only D I and III only E II and III only Q5. A ball is thrown horizontally from a cliff as

shown. The effect of air resistance is negligible. A student makes the following statements about the ball.

I The vertical speed of the ball increases as it falls. II The vertical acceleration of the ball increases as it falls. III The vertical force on the ball increases as it falls.

Which of the statements is/are correct? A I only B II only C I and II only D II and III only E I, II and III

X Y#

Sea level

Q6. A package is released from a helicopter flying horizontally at a constant speed of 40 ms-1.

The package takes 3·1 s to reach the ground. The effects of air resistance can be ignored. Which row in the table shows the horizontal speed and vertical speed of the package just before it hits the ground?

Q7. A ball rolls down a runway and leaves it at point R. The horizontal speed of the ball at R is 1.5ms-1. The ball takes 0.6s to travel from R to T. The distance ST is A 0.40m B 0.90m C 2.5m D 9.0m

E 15m.

Horizontal speed (ms-1)

Vertical speed (ms-1)

A 0 30

B 30 30

C 30 40

D 40 30

E 40 40

Q8. A ball is kicked horizontally off the edge of a cliff and lands in the sea. Which pair of graphs shows the horizontal and vertical speeds of the ball during its flight? The effect of air friction should be ignored.

Time

Horizontal Speed

Time

Vertical Speed

Time

Horizontal Speed

Time

Vertical Speed

Time

Horizontal Speed

Time

Vertical Speed

Time

Horizontal Speed

Time

Vertical Speed

Time

Horizontal Speed

Time

Vertical Speed

A

B

C

D

E

Q9. A satellite is in a circular orbit around a planet.

A group of students make the following statements about the satellite. I The greater the altitude of a satellite the shorter its orbital period. II The satellite has a constant vertical acceleration. III As the satellite orbits the planet, its vertical velocity increases. Which of these statements is/are correct? A I only B II only C III only D I and II only E II and III only

Q10. A ball is thrown vertically upwards. The ball reaches its maximum height. Which of the following describes the forces acting on the ball at this instant? A There is no vertical force acting on the ball. B There is only a horizontal force acting on the ball. C There is an upward force acting on the ball. D The forces acting on the ball are balanced. E There is only a downward force acting on the ball.

Planet

satellite

Projectiles Extended Response Questions Q1. In a TV game show contestants are challenged to run off a horizontal

platform and land in a rubber ring floating in a swimming pool. The platform is 2·8 m above the water surface.

A contestant has a mass of 60 kg. He runs off the platform with a horizontal velocity of 2.0ms-1. He takes 0·75 s to reach the water surface in the centre of the ring.

a. Calculate the horizontal distance X from the poolside to the centre of the ring. (3) b. Calculate the vertical velocity of the contestant as he reaches the water surface. (3) c. Another contestant has a mass of 80 kg. Will she need to run faster,

slower or at the same horizontal speed as the first contestant to land in the ring?

You must explain your answer. (2)

2·8

Q2. A cricketer strikes a ball. The ball leaves the bat horizontally at 20 ms-1. It hits the ground at a distance of 11 m from the point where it was struck.

Assume that air resistance is negligible.

a. Calculate the time of flight of the ball. (3) b. Calculate the vertical speed of the ball as it reaches the ground. (3) c. Sketch a graph of vertical speed against time for the ball. Numerical

values are required on both axes. (3) d. Calculate the vertical distance travelled by the ball during its flight. (3)

Q3. At a firing range a pellet is fired horizontally at a target 40m away. It

takes 0.20s to reach the target.

Calculate the vertical velocity of the pellet on reaching the target. (3)

Q4. The ISS orbits at a height of approximately 360 km above the

Earth. Explain why the ISS stays in orbit around the Earth. (2)

Q5. During a part of the competition, the cyclist and bike travel horizontally

at 6.0ms−1 off a ledge as shown.

a. On the diagram above, sketch the path taken by the cyclist and bike

between leaving the ledge and reaching the ground. (1)

b. The cyclist and bike reach the ground 0.40 s after leaving the ledge. Calculate the vertical velocity of the cyclist and bike as they reach the ground.

The effects of air resistance can be ignored. (3)

Ground

Ledge

6.0ms−1