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Physics 4A
Spring 2017
Name ___________________________________
Lab: morning
afternoon evening
(circle one)
Quiz #1: Measurement and One Dimensional Motion
Problem 1 (2 points)
A particle moves along the x-axis. When its acceleration is positive and increasing:
a) its velocity must be positive
b) its velocity must be negative
c) it must be slowing down
d) it must be speeding up
e) none of the above must be true
Problem 2 (3 points)
Newton’s Law of Universal Gravitation states that the force between two masses m1 and m2, separated by a
distance r is given by F =
Gm1m2
. Force has units of kg m/s2. What are the units of the gravitational constant
2
r
G?
Problem 3 (5 points)
The position of an object is given as a function of time by the equation:
=
x (3.0 m/s3 )t 3 − (12.0 m/s2 )t 2 .
a) What is the object’s average velocity between t = 1.0 s and t = 3.0 s?
b) What is the object’s average acceleration between t = 1.0 s and t = 3.0 s?
c) What is the object’s acceleration at t = 3.0 s?