Transcript MC Practice #1 Ekina momuntum starter

Chapter 5 Clickers
Impulse and Linear
Momentum
Prepared by
Dedra Demaree,
Georgetown University
© 2014 Pearson Education, Inc.
Which of the following statements is NOT a pattern
observed in the set of three observational
experiments with colliding carts?
a) The kinetic energy of the carts remained the same
before and after the collision.
b) The total mass of the carts remained the same
before and after the collision.
c) The sum of the products of the mass and velocity
of the carts remained the same before and after
the collision.
d) The color of the carts remained the same before
and after the collision.
© 2014 Pearson Education, Inc.
Which of the following statements is NOT a pattern
observed in the set of three observational
experiments with colliding carts?
a) The kinetic energy of the carts remained the
same before and after the collision.
b) The total mass of the carts remained the same
before and after the collision.
c) The sum of the products of the mass and velocity
of the carts remained the same before and after
the collision.
d) The color of the carts remained the same before
and after the collision.
© 2014 Pearson Education, Inc.
Which of the following statements is NOT correct
about linear momentum?
a) Linear momentum is a vector quantity.
b) Linear momentum is conserved in a collision.
c) Linear momentum is independent of reference
frame.
d) Linear momentum is the product of a system
object's mass and velocity.
© 2014 Pearson Education, Inc.
Which of the following statements is NOT correct
about linear momentum?
a) Linear momentum is a vector quantity.
b) Linear momentum is conserved in a collision.
c) Linear momentum is independent of reference
frame.
d) Linear momentum is the product of a system
object's mass and velocity.
© 2014 Pearson Education, Inc.
Jen (50 kg) and David (75 kg), both on rollerblades,
push off each other abruptly. After the push, Jen has
a velocity of -3.0 m/s. What is David's velocity?
a)
b)
c)
d)
+2.0 m/s
+3.0 m/s
+4.5 m/s
Not enough information is given to determine
David's velocity.
© 2014 Pearson Education, Inc.
Jen (50 kg) and David (75 kg), both on rollerblades,
push off each other abruptly. After the push, Jen has
a velocity of -3.0 m/s. What is David's velocity?
a)
b)
c)
d)
+2.0 m/s
+3.0 m/s
+4.5 m/s
Not enough information is given to determine
David's velocity.
© 2014 Pearson Education, Inc.
Two identical carts travel toward each other at the
same speed and collide with each other. What can
we conclude?
a) The final linear momentum of the two carts will sum
to zero.
b) The carts will have zero velocity after the collision.
c) After the collision, the carts will be moving with the
same speed but in opposite directions.
d) We cannot reach any of these conclusions.
© 2014 Pearson Education, Inc.
Two identical carts travel toward each other at the
same speed and collide with each other. What can
we conclude?
a) The final linear momentum of the two carts will
sum to zero.
b) The carts will have zero velocity after the collision.
c) After the collision, the carts will be moving with the
same speed but in opposite directions.
d) We cannot reach any of these conclusions.
© 2014 Pearson Education, Inc.
A 1000-kg car is moving at 10 m/s with respect to the
ground when the car hits a barrier. The car is
stopped in 0.5 s by the force of the barrier on the car.
What is the magnitude of the average force the
barrier exerted on the car during the collision?
a)
b)
c)
d)
2000 N
5000 N
20,000 N
Impossible to determine from the information given
© 2014 Pearson Education, Inc.
A 1000-kg car is moving at 10 m/s with respect to the
ground when the car hits a barrier. The car is
stopped in 0.5 s by the force of the barrier on the car.
What is the magnitude of the average force the
barrier exerted on the car during the collision?
a)
b)
c)
d)
2000 N
5000 N
20,000 N
Impossible to determine from the information given
© 2014 Pearson Education, Inc.
Consider the happy ball and the sad ball. If dropped
from a height h, the sad ball does not bounce and
the happy ball bounces back to its original height.
Which of the following statements is NOT correct?
a) The final momentum of the sad ball is zero.
b) The final momentum of the happy ball is equal in
magnitude to its initial momentum.
c) The change in the momentum of the sad ball is
larger than the change in the momentum of the
happy ball.
d) The impulse exerted on the happy ball is greater
than the impulse exerted on the sad ball.
© 2014 Pearson Education, Inc.
Consider the happy ball and the sad ball. If dropped
from a height h, the sad ball does not bounce and
the happy ball bounces back to its original height.
Which of the following statements is NOT correct?
a) The final momentum of the sad ball is zero.
b) The final momentum of the happy ball is equal in
magnitude to its initial momentum.
c) The change in the momentum of the sad ball is
larger than the change in the momentum of the
happy ball.
d) The impulse exerted on the happy ball is greater
than the impulse exerted on the sad ball.
© 2014 Pearson Education, Inc.
Consider the happy ball (mh) and the sad ball (ms). If
dropped from a height h, the sad ball does not
bounce and the happy ball bounces back to its
original height. Which of the following equations is
NOT correct? (Take "up" to be the positive axis.)
a)
b)
c)
d)
e)
ms(-vi) + Js = 0
mh(-vi) + Jh = mh(+vf)
ms(-vi) = mh(-vi)
|mh(-vi)| = |mh(+vf)|
They are all correct.
© 2014 Pearson Education, Inc.
Consider the happy ball (mh) and the sad ball (ms). If
dropped from a height h, the sad ball does not
bounce and the happy ball bounces back to its
original height. Which of the following equations is
NOT correct? (Take "up" to be the positive axis.)
a)
b)
c)
d)
e)
ms(-vi) + Js = 0
mh(-vi) + Jh = mh(+vf)
ms(-vi) = mh(-vi)
|mh(-vi)| = |mh(+vf)|
They are all correct.
© 2014 Pearson Education, Inc.
Consider the happy ball (mh) and the sad ball (ms). If
dropped from a height h, the sad ball does not
bounce and the happy ball bounces back to its
original height. Which of the following equations is
NOT correct? (Take "up" to be the positive axis.)
a)
b)
c)
d)
|Js| = |ms(-vi)|
|Jh| = |2mh(-vi)|
|Jh| = 2|Js|
They are all correct.
© 2014 Pearson Education, Inc.
Consider the happy ball (mh) and the sad ball (ms). If
dropped from a height h, the sad ball does not
bounce and the happy ball bounces back to its
original height. Which of the following equations is
NOT correct? (Take "up" to be the positive axis.)
a)
b)
c)
d)
|Js| = |ms(-vi)|
|Jh| = |2mh(-vi)|
|Jh| = 2|Js|
They are all correct.
© 2014 Pearson Education, Inc.
Based on the impulse applied to each ball and
Newton's third law, which ball will apply a bigger
impulse to an object it hits?
a) The happy ball will apply the larger impulse.
b) The happy ball and the sad ball will apply the same
impulse.
c) The sad ball will apply the larger impulse.
© 2014 Pearson Education, Inc.
Based on the impulse applied to each ball and
Newton's third law, which ball will apply a bigger
impulse to an object it hits?
a) The happy ball will apply the larger impulse.
b) The happy ball and the sad ball will apply the same
impulse.
c) The sad ball will apply the larger impulse.
© 2014 Pearson Education, Inc.
An impulse-momentum bar chart describes the
following situation: A bullet is fired horizontally into a
block of wood resting on a table. Immediately after
the bullet joins the block, the block and the bullet
move together in the positive x-direction. Which
equation is correct?
a)
b)
c)
d)
e)
mBvBi + mwvwi + J = mBvBf + mwvwf
mBvBi + 0 + 0 = mBvBf + mwvwf
mBvBi + mwvwi + J = (mB + mw)vf
mBvBi + 0 + 0 = (mB + mw)vf
They are all correct.
© 2014 Pearson Education, Inc.
An impulse-momentum bar chart describes the
following situation: A bullet is fired horizontally into a
block of wood resting on a table. Immediately after
the bullet joins the block, the block and the bullet
move together in the positive x-direction. Which
equation is correct?
a)
b)
c)
d)
e)
mBvBi + mwvwi + J = mBvBf + mwvwf
mBvBi + 0 + 0 = mBvBf + mwvwf
mBvBi + mwvwi + J = (mB + mw)vf
mBvBi + 0 + 0 = (mB + mw)vf
They are all correct.
© 2014 Pearson Education, Inc.
A 50-kg stunt diver is falling at a speed of 20 m/s
when she is stopped by sinking into a cushion that
exerts an average force of 500 N on her. How much
time did it take her to stop moving once she hit the
cushion?
a)
b)
c)
d)
0.5 second
1.0 seconds
2.0 seconds
5.0 seconds
© 2014 Pearson Education, Inc.
A 50-kg stunt diver is falling at a speed of 20 m/s
when she is stopped by sinking into a cushion that
exerts an average force of 500 N on her. How much
time did it take her to stop moving once she hit the
cushion?
a)
b)
c)
d)
0.5 second
1.0 seconds
2.0 seconds
5.0 seconds
© 2014 Pearson Education, Inc.
Which of the following is NOT an assumption we
need to make to solve jet propulsion problems
without calculus?
a) We need to assume the jet is moving through
air.
b) We need to assume the fuel burns very quickly.
c) We need to assume there is negligible change in
mass during the thrust.
d) We need to assume all of the above.
© 2014 Pearson Education, Inc.
Which of the following is NOT an assumption we
need to make to solve jet propulsion problems
without calculus?
a) We need to assume the jet is moving through
air.
b) We need to assume the fuel burns very quickly.
c) We need to assume there is negligible change in
mass during the thrust.
d) We need to assume all of the above.
© 2014 Pearson Education, Inc.
Which of the following statements is NOT true about
applying the impulse-momentum principle to
two-dimensional collisions?
a) If the impulse is zero, the magnitude of the
system's initial momentum equals the magnitude of
its final momentum.
b) If the impulse is zero, the system's initial
momentum along the x-axis equals its final
momentum along the x-axis.
c) If the impulse is zero, the system's initial
momentum along the y-axis equals its final
momentum along the y-axis.
© 2014 Pearson Education, Inc.
Which of the following statements is NOT true about
applying the impulse-momentum principle to
two-dimensional collisions?
a) If the impulse is zero, the magnitude of the
system's initial momentum equals the
magnitude of its final momentum.
b) If the impulse is zero, the system's initial
momentum along the x-axis equals its final
momentum along the x-axis.
c) If the impulse is zero, the system's initial
momentum along the y-axis equals its final
momentum along the y-axis.
© 2014 Pearson Education, Inc.