Physics 3A: Basic Physics I
Quiz #2a: Solutions
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9.80 m
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32.0 ft
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(circle the letter of your answer)
1. (2 pts) Which of the following statements is false?
a.) The instantaneous velocity can be โalwaysโ equal to the average velocity
during a given time interval with a non-zero acceleration.
b.) The average velocity vector can be zero if the average speed is non-zero.
c.) The instantaneous velocity can be smaller than the average velocity.
d.) The instantaneous velocity can be larger than the average velocity.
2. (2 pts) You just graduated from UCI! You throw your cap straight up into the air. It
goes up, stops and then comes back down. During which part of the motion is the
acceleration vector of the cap upward, toward the sky?
a.) When you first let go of the cap and it starts upward.
b.) When the cap is at its highest point and its velocity is zero.
c.) When the cap is falling back down to the ground
d.) All of the above
e.) None of the above
3. (6 pts) Late as usual, Tony rushes down onto a subway platform to find his train
already departing. He stops and watches the cars go by. Each car is 10.5 m long. The
first moves past me, I mean him, in 1.25 s and the second in 1.00 s. What is the
constant acceleration of the train? (use back of sheet as well, circle your final
answer and show all work)
