Momentum and Collisions Name:
Momentum, Impulse and Momentum Change
Read from Lesson 1 of the Momentum and Collisions chapter at The Physics Classroom:
http://www.physicsclassroom.com/Class/momentum/u4l1a.cfm
http://www.physicsclassroom.com/Class/momentum/u4l1b.cfm
MOP Connection: Momentum and Collisions: sublevels 1 and 2
Momentum
1. The momentum of an object depends upon the object's ___A, D___. Pick two quantities.
a. mass  how much stuff it has
b. acceleration  the rate at which the stuff changes its velocity
c. weight  the force by which gravity attracts the stuff to Earth
d. velocity  how fast and in what direction it's stuff is moving
e. position  where the stuff is at
2. Momentum is a ___vector___ quantity.
a. scalar b. vector
3. Which are complete descriptions of the momentum of an object? Circle all that apply. __B, E__
a. 2.0 kg/s b. 7.2 kg•m/s, right c. 6.1 kg•m/s^{2}, down
d. 4.2 m/s, east e. 1.9 kg•m/s, west f. 2.3 kg•m/s
(Proper units  kg•m/s  and a direction are required.)
4. The two quantities needed to calculate an object's momentum are __mass__ and __velocity__.
5. Consider the mass and velocity values of Objects A and B below. Compared to Object B, Object A has _two times the_ momentum.
a. two times the b. four times the
c. eight times the d. the same
e. onehalf the f. onefourth the
g. ... impossible to tell without knowledge of the F and a.


6. Calculate the momentum value of ... . (Include appropriate units on your answers.)
a. ... a 2.0kg brick moving through the air at 12 m/s.
p = m•v = (2.0 kg)•(12 m/s) = 24 kg•m/s
b. ... a 3.5kg wagon moving along the sidewalk at 1.2 m/s.
p = m•v = (3.5 kg)•(1.2 m/s) = 4.2 kg•m/s
7. With what velocity must a 0.53kg softball be moving to equal the momentum of a 0.31kg baseball moving at 21 m/s?
p_{softball} = p_{baseball}
(0.53 kg)•v_{softball} = (0.31 kg)•(21 m/s)
v_{softball} = 12m/s
Impulse and Momentum Change
8. Insert these words into the four blanks of the sentence: mass, momentum, acceleration, time, impact, weight, impulse, and force. (Not every word will be used.)
In a collision, an object experiences a(n) ____force____ acting for a certain amount of _____time_____ and which is known as a(n) __impulse__ ; it serves to change the __momentum__ of the object.


9. A(n) ___impulse___ causes and is equal to a change in momentum.
a. force b. impact c. impulse d. collision
10. Calculate the impulse experienced by .... . (Show appropriate units on your answer.)
a. ... a 65.8kg halfback encountering a force of 1025 N for 0.350 seconds.
Impulse = F•t = (1025 N)•(0.350 s) = 359 N•s
b. ... a 0.168kg tennis ball encountering a force of 126 N that changes its velocity by 61.8 m/s.
Impulse = ∆momentum =m•∆v = (0.168 kg)•(61.8 m/s) = 10.4 kg•m/s = 10.4 N•s
11. Determine the impulse (I), momentum change (p), momentum (p) and other values.
A 7ball collides with the 8ball. A moving medicine ball is caught by a girl on ice skates.
A car is at rest when it experiences a forward propulsion force to set it in motion. It then experiences a second forward propulsion force to speed it up even more. Finally, it brakes to a stop.
A tennis ball is at rest when it experiences a forward force to set it in motion. It then strikes a wall where it encounters a force that slows it down and finally turns it around and sends it backwards.
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