1ST DAY LAB:VASCAR & White Lines

Collect data of the times of 5 cars and record on index card. Return and hold onto card.

•DISTANCE

•SPEED

•AVERAGE SPEED

•INSTANTANEOUS SPEED

•CONSTANT SPEED?

DEFINE:

Complete the speed trap lab

SPARK TIMER LAB – CONSTANT SPEED?

Compare the motion of the tapes for the:i)top situation ii)bottom situation.

VELOCITY vs SPEED

• Velocity =

•Sign of velocity (+ or - ) means direction of object. •Negative doesn’t mean less than 0.•Minus (-) is left or down + is right or up

Ways to accelerate:

ACCELERATION

Describe the motion of each spark tape.

ACCELERATION or DecelerationAn object that has a ZERO acceleration means

the velocity of the object is _________________.

What two kinds of possible motion could occur with a zero acceleration?

Constant Acceleration means an object is changing its velocity by _______________

Acceleration tells velocity how

Deceleration means

Constant Acceleration Equations

Assume all objects start from rest.

Example An airplane accelerates down a runway at 3.2 m/s2 for 32.8sec until it finally lifts off the ground.a)Determine the distance traveled before takeoff.b)Determine the takeoff speed.

A sheep accelerates uniformly across the HS courtyard from rest to a speed of 7.1m/s over a distance of 35.4m.

Example

a) Determine the acceleration of the sheep.

b) Calculate the time it took to accelerate.

Heavy vs Light objects

Which falls faster?

FREEFALL andACCELERATION DUE TO GRAVITY

Freefall is a condition where an object is ONLY experiencing Earth’s gravitational pull with NO air resistance or minimal air resistance. The object can be moving downwards or upwards.

Acc due to gravity = ‘g’Freefall equations

2/10 smg

*These equations are only good if object falls from rest

Gravity causes objects to EITHER gain speed downward or lose speed moving upward (a=g=10m/s2 ). What is speed of the ball at the peak of flight?

What is the acceleration of the ball on the way up?

What is the acceleration of the ball on the way down?

What is the acceleration of the ball at the peak?

Determine his speed after 35sec of freefall.

How far did he fall in that time?

a) Calculate his speed after falling 40ft. Convert ft to meters.

b) Calculate the time of fall for 40ft. Convert ft to meters.

a) Dwight Howard’s had vertical leap of 39.5”. Determine how much time it would take to fall that distance from rest.

b) Calculate how fast he takes off based on the time from above.

Relative velocityDESCRIBES motion of an object compared to the motion of something else.

a) How fast does the person on the train move relative to the ground?

b) How fast does this person move relative to ground if they walk in opposite direction?

Refueling of airplanes in midflight. How fast must smaller jet fly relative to refueling plane in order to get refueled?

Treadmill mill is moving 10mph backwards relative to floor. Man is running 10mph forward relative to belt.

How fast is man moving relative to floor?

A person holds a red ball while standing in an elevator. If the cable snaps and elevator begins to fall, what happens to the ball if person releases it while falling?

How fast are people in vomit comet falling relative to plane while plane falls?

NO such thing as zero ‘g’

i. Why is there no zero ‘g’?

ii. Why is the term used if it is a false statement?

iii. What is it about freefall that makes people think gravity has reduced to a zero value?