Momentum

Unit for impulse

Ns

Automobile dashboards that are padded INCREASE the time of impact in the case of a collision (True or False)

True

When two objects collide and completely stick together, the collision is said to be inelastic. (True or False)

True

Symbol for velocity

V

A collision is considered INELASTIC if _____________. a) the objects "stick" together b) the objects "bounce" off of one another c) the objects start together and then separate d) all of the above

a) the objects "stick" together

The reason padded dashboards are used in cars is that they _____. a) decrease the IMPULSE in a collision b) increase the TIME of impact in a collision c) increase the FORCE of impact in a collision

b) increase the time of impact in a collision

The momentum of an object is calculated by __________. a) mass x acceleration b) mass x velocity c) velocity x time d) force x time

b) mass times its velocity

Which has more momentum, a large truck moving at 30 miles per hour or a small tuck moving at 30 miles per hour? a) the small truck b) the large truck c) both have the same momentum

b) the large truck

A collision is considered ELASTIC if _____________. a) the objects "stick" together b) the objects "bounce" off of one another c) the objects start together and then separate d) all of the above

b) the objects "bounce" off of one another

Which of the following has the largest momentum? a) a dog running down the street b) the science building at your school c) a pickup truck traveling down the highway

c) a pickup truck traveling down the highway

If the momentum of an object changes and its mass remains constant, _____________. a) its velocity is changing b) there is a force acting on it c) all of the above

c) all of the above

A collision is considered EXPLOSION if _____________. a) the objects "stick" together b) the objects "bounce" off of one another c) the objects start together and then separate d) all of the above

c) the objects start together and then separate

Compared to a sports car moving at 30 miles per hour, the same sports car moving at 60 miles per hour has ________. a) four times as much momentum b) the same momentum c) twice as much momentum

c) twice as much momentum

Impulse is defined as

change in momentum

The impulse of an object is calculated by __________. a) mass x acceleration b) mass x velocity c) velocity x time d) force x time

d) force x time

With impulse, to DECREASE the force felt you need to _________ the time before impact (the collision)

increase

Unit for mass

kg

Unit for momentum

kgm/s

Symbol for mass

m

Momentum is defined as

mass in motion

Unit for velocity

meters per second

Symbol for momentum

p

Unit for time

s

Symbol for time

t

A ball is moving at 4 m/s and has a momentum of 48 kg m/s. What is the ball's mass? SOLVE FOR M. p=mv 48=(m)(4 m/s)

12 kg

What is the average momentum of a 5kg runner who covers 400m in 50s? SOLVE FOR MOMENTUM. p=mxv v= 400m/50s = 8m/s (50kg)(8m/s)=400 kg*m/s

400 kg*m/s

A 2kg ball is thrown at 3 m/s. What is the ball's momentum? SOLVE FOR P. p=mv p=(2kg)(3 m/s)

6 kgm/s

Impulse is defined as the FORCE exerted on an objects multiplied by the ACCELERATION. (True or False)

False

When two objects collide and completely bounce apart with no lasting deformation or general heat, the collision is said to be inelastic. (True or False)

False

Symbol for impulse

I