DP Physics Paper 1M13/4/PHYSI/SPM/ENG/TZ1/XX

1. The mass of an elephant is 104 kg. The mass of a mouse is 10–2 kg. What is the ratio

mass of the elephant

mass of the mouse

A. 10-8 B. 10-6 C. 106 D. 108

104+2 = 106

2. An archer aims five arrows at the centre of a target. The arrows strike the target as shown below.

Which of the following describes the aim of the archer?

A. Accurate and precise

B. Accurate but not precise

C. Precise but not accurate

D. Neither accurate nor precise

Accuracy refers to the degree of conformity and correctness of something when compared to a true or absolute value, while precision refers to a state of strict exactness — how consistently something is strictly exact.

3. The graph below shows how velocity v varies with time t for a ball thrown vertically upwards from the Earth’s surface.

The shaded area is equal to the

A. displacement.

B. final velocity.

C. change in velocity.

D. acceleration.

Area of a triangle is ½ bh = ½ (time)(displacement/time) Cancel time and get displacement.

4. Two identical balls are dropped from a tall building, one a few seconds after the other. Air resistance is not negligible. As the balls fall, the distance between the balls will

A. decrease. B. increase.

C. increase then remain constant. D. remain constant.

time rock 1 distance rock 2 distance separation

1 5

2 20 5 15

3 45 20 25

4 80 45 35

5 125 80 45

6 180 125 55

7 245 180 65

8 320 245 75

9 405 320 85

10 500 405 95

11 600 500 100

12 700 600 100

13 800 700 100

14 900 800 100

15 1000 900 100

16 1100 1000 100

17 1200 1100 100

18 1300 1200 100

19 1400 1300 100

Rock 2 is released 1 secondafter rock 1. Both rocks reached terminal velocity after 10 seconds.

5. Which of the following is always true for an object moving in a straight line at constant speed?

A. No forces act on the object.

B. No resultant force acts on the object.

C. The momentum of the object is zero.

D. No work is being done on the object.

Fapplied

F Normal

Weight

Ffriction

6. A person of weight 600N is standing on a weighing scale in a lift (elevator). The lift is accelerating upwards at 1.0ms–2. Which of the following is the reading on the scale?

A. 0N B. 540N C. 600N D. 660N

F = ma = 600 (10 + 1) = 660 N

7. A spaceship is moving at constant speed in outer space. An internal explosion causes it to break into two pieces that move in opposite directions. Which of the following best describes what happens to its total momentum and total kinetic energy as a result of the explosion?

The law of conservation of momentum states that, in the absence of an external force, the momentum of a system remains unchanged.

The law of conservation of energy states that energy cannot be created or destroyed. It can be transformed from one form into another, but the total amount of energy never changes. The kinetic energy increased from the conversion of chemical toKinetic Energy from the explosion.

8. A horizontal disc is rotating about a vertical axis through its centre. Points P and Q on the disc are at distances R and 2R respectively from the centre.

The acceleration at P is a. Which of the following is the acceleration at Q?

A. 0.5a B. a C. 2a D. 4a

aarT

rT

a

arTT

ra

Q

P

2)2()2(4

24

44

2

2

2

2

2

2

2

2

9. 4.0kg of water at 100°C is mixed with 1.0 kg of water at 0°C in a container insulated from the surroundings. Which of the following is the final temperature of the water?

A. 20°C B. 25°C C. 75°C D. 80°C

CT

T

TT

TkgTkg

TTmCTTmC

QQ

F

F

FF

FF

IFPIFP

lostgain

80

4005

44001

100401

10. Which of the following best describes the evaporation of a liquid?

Evaporation occurs only at the surface of a liquid and can occur at any temperature.

Evaporation can be enhanced by increasing the surface area, warming the liquid, or having air movement at the surface.

(Powerpoint 3.1 slide 28)

11.

Which of the following is the temperature of an object related to?

A. The kinetic energy of the object

B. The random kinetic energy of the particles in the object

C. The potential energy of the particles in the object

D. The sum of the random kinetic energy and potential energy of the particles in the object

As we heat up a substance its vibrations become more energetic. This is an increase in the kinetic energy of the molecules.

The thermometer measures internal kinetic energy

(Powerpoint 3.1 slide 10 and 11)

12. The acceleration of an object executing simple harmonic motion is proportional to the

A. displacement of the object from equilibrium.

B. velocity of the object.

C. amplitude of oscillation.

D. frequency of oscillation.

Objects can oscillate in all sorts of ways but a really important form of oscillation is SHM or Simple Harmonic Motion.An object is undergoing simple harmonic motion (SHM) if;the acceleration of the object is directly proportional to its displacement from its equilibrium position.the acceleration is always directed towards the equilibrium position.The frequency (f) of an oscillation is measure in hertz (Hz) it is the number of oscillations per second. The time for one oscillation is called the period (T) it is measured in seconds.

Acceleration – we can calculate the acceleration of the object at any point in it’s oscillation using the equation below.In this equation; a = acceleration in ms-2, f = frequency in Hz, x = displacement from the central position in m.

http://physicsnet.co.uk/a-level-physics-as-a2/further-mechanics/simple-harmonic-motion-shm/

or

In simple harmonic motion (SHM), a and x are related in a very precise way: Namely, a -x.

PE = 1/2kx2

F = -kx

ma = -kx

a = (-k/m) x

13.

A system, consisting of a mass M connected to a spring, oscillates

on a frictionless surface with simple harmonic motion between two points, X and Y. Point O is the centre of the oscillation.

For the system, at which of the following points is the elastic

potential energy equal to the kinetic energy?

A. O only

B. X and Y only

C. O, X and Y

D. Neither O, X nor Y

Max KE0 PE

Max PE0 KE

Max PE0 KE

14. Microwave ovens cause the water molecules in food to resonate. Water molecules have a natural frequency of vibration f. In order to heat the food most effectively, the frequency of the microwaves should have a value

A. less than f.

B. equal to f .

C. greater than f.

D. as large as possible.

Microwaves are absorbed by some of the chemicals in foods—most optimally water. This is because water molecules are polar, meaning that the distribution of charge within the molecule is not symmetrical; one side of the molecule is slightly positive, and the other is slightly negative. Thus, in the presence of the electric field component of a microwave, a force will be applied to both dipoles of the molecule which will cause it to rotate (Heckert 2007). In Figure 4, two water molecules are shown in the positions where the force on their dipoles due to the electric field of a wave is at a minimum.Figure 4: The rotation of water molecules under the influence of the electric field component in an electromagnetic wave. (Black arrows represent electric field.)

Because the electric field is continually oscillating, the water molecules continually rotate. The frequency of microwaves (2.45 GHz) is optimal because the time it takes for the electric field to oscillate is consistent with the time it takes for a water molecule to rotate 180° (Heckert 2007). Thus, the water molecules are rotating as quickly as possible.

As the water molecules rotate, they bump into other molecules surrounding them and transfer some of their kinetic energy. By the Kinetic Particle Theory, if the particles in the food have more kinetic energy, then the food will be hotter.

15. Gas particles are equally spaced along a straight line. A sound wave passes through the gas. The positions of the gas particles at one instant are shown below. Which of the distances shown is equal to the wavelength of the wave?

The wavelength of a wave is the distance from the top of one crest to the top of the next one. One complete cycle.

Twice the wavelength

Half the wavelength

16. A particle with positive charge +q moves freely from one plate held at potential V1 to another plate held at potential V2.

DPE = charge (V2 – V1)= q (V2 – V1)

17. Which of the following graphs shows the relationship between current I and voltage V for a filament lamp?

The temperature coefficient is positive, typical

for conductors.

Therefore, the hotter the filament the higher R.

But the more current, the hotter a lamp filament

burns.

Thus, the bigger the I the bigger the R.(powerpoint 5.2, slide 23)

18.Acell of negligible internal resistance is connected to three identical lamps. A voltmeter is connected across one of the lamps.

If the filament in lamp X breaks, the reading on the voltmeter will

A. become zero.

B. decrease.

C. stay the same.

D. increase.

Parallel circuits decrease resistance and series circuits increase resistance.Losing the lamp at X would create a series circuit and decrease voltageat the voltmeter.

19. The gravitational field strength at the surface of a certain planet is g. Which of the following is the gravitational field strength at the surface of a planet with twice the radius and twice the mass?

A. g/2 B. g C. 2g D. 4g

g = GM / r 2

g = G(2M)/(2r)2

g = 2GM/(4r2)

g = ½ GM/r2 = ½ g

20. Two point charges of size +2q and –q are placed as shown below. In which of the regions I, II and III can the resultant electric field strength be zero?

A. I only

B. II only

C. III only

D. I and III only Electric field sensors

+2q -q

21. A wire is placed in a magnetic field which is directed to the right. The wire carries a current directed into the page. Which of the following is the direction of the force on the wire?

22.Which of the following would decrease the initial activity of a sample of plutonium?

A. Placing the sample in a lead container

B. Placing the sample in a dark room

C. Decreasing the mass of the sample

D. Decreasing the temperature of the sample

The decay rate or activity A is proportional to the population of the radioactive nuclide N0 in the sample

Not D - n 1913, Pierre Curie and M. Kamerlingh Onnes measured the rate of decay of radium at room temperature and after being cooled in liquid hydrogen. Their conclusion was that the decay rate was entirely independent of temperature.

Decay rates of radioactive substances are constant

Lead blocks or diminish the affect of radiation but does not affect the rate of radioactivity.

23. A radioactive sample of initial activity 12Bq has a half-life of 3 days. What is the activity after 6 days?

A. 2Bq B. 3Bq C. 4Bq D. 6Bq

Initial - 12Bq

3 days later – 6 Bq

6 days later – 3 Bq

24. The reaction is an example of

A. alpha decay. B. artificial transmutation.

C. nuclear fusion. D. proton decay.

Not A – alpha particle was not a result of the reaction

Not C – fusion does not release protons

Not D – In particle physics, proton decay is a hypothetical form of radioactive decay in which the proton decays into lighter subatomic particles, such as a neutral pion and a positron. There is currently no experimental evidence that proton decay occurs.

25. The diagram below shows an energy flow diagram (Sankeydiagram) for a car.

What is the efficiency of the car?

A. 30% B. 40% C. 70% D. 100%

26. A small biofuel power station burns ethanol with an overall efficiency of 25%. The energy density of ethanol is 30MJkg–1. The mass of fuel consumed every second is 50kg. Which of the following gives the useful power output in MW?

100

/305025 kgMJkgoutput

inputefficiencyoutput

input

outputefficiency

27. An oscillating water column ocean-wave energy converter produces power P from waves of a certain amplitude and wavespeed. Which of the following would be the power produced from waves of twice the amplitude and twice the wavespeed?

A. 2P B. 4P C. 8P D. 16P

NO LONGER PART OF THE COURSE

28. The total power radiated by the Sun is P. The distance from the Sun to the Earth is d. The albedo of the Earth is α. What is the power absorbed by each square metre of the Earth’s surface?

albedo = PSCATTERED / PINCIDENT

= PSCATTERED/PINCIDENT

PSCATTERED = · PINCIDENT

PABSORBED = PINCIDENT – PSCATTERED

PABSORBED = PINCIDENT – · PINCIDENT

PABSORBED = PINCIDENT (1 – )

I = power / A A = 4d2

I = 𝑃𝐼𝑁𝐶𝐼𝐷𝐸𝑁𝑇(1 −𝛼)

4𝜋𝑑2

29. Carbon dioxide is a greenhouse gas because

A. it absorbs infrared light radiated by the Sun.

B. it absorbs ultraviolet light radiated by the Earth.

C. its natural frequency molecular oscillation lies in the infrared region.

D. its natural frequency molecular oscillation lies in the ultraviolet region

30. Which of the following is most likely to increase the rate of global warming?

A. Deforestation

B. Increasing the use of nuclear power stations

C. Increasing the use of renewable energy sources

D. Using natural gas instead of coal for electricity generation