Ap Physics Worksheet With Answers (Page 5 of 8) in pdf

Ap Physics Worksheet With Answers Page 5

35. Two dynamics carts, on a frictionless surface, are blasted apart by the spring between them.

If cart B moves off at + 5.0 m/s, what is the velocity of cart A? Use a momentum bar chart in your response.

Cart A

Cart B

Momentum Vector Diagram

BEFORE

AFTER

pA + pB = pA’ + pB’

0 = pA’ + pB’

pA’ = -pB’

mAvA = -mBvB

vA = (-mBvB)/mA

vA = - [(2.8 kg)(5.0 m/s)]/(1.16 kg) = 121 m/s

36. An arrow weighing 0.10 kg travelling at 80 m/s is shot into a straw target suspended by a rope. You are given that the target

weighs 7.0 kg and that the arrow sticks inside the target. Calculate the velocity of the target immediately after being pierced by the

arrow. Use a momentum bar chart in your response.

Arrow

Target

Momentum Vector Diagram

BEFORE

AFTER

p(arrow) + p(target) = p(arrow)’ + p(target)’

v(arrow + target)’ = m(arrow)v(arrow)/ m(arrow + target)

p(arrow) +0 = p(arrow)’ + p(target)’

v(arrow + target)’ = (0.10 kg)(80 m/s)/(7.1 kg)

p(arrow) +0 = p(arrow + target)’

v(arrow + target)’ = 1.13 m/s

p(arrow + target)’ = p(arrow)

m(arrow + target)v(arrow + target)’ = m(arrow)v(arrow)

Note: arrow is embedded in target; combined unit has

same velocity

Ap Physics Worksheet With Answers Page 5