Download Exam 1 - USU Physics

2 February 2011
Physics 2200/2210
Exam 1
Class PIN
Please give all your answers in 3 significant figures
And remember units!
Closed Book
Equation Sheets Permitted (Unmarked)
Non-programmed Calculators Permitted
True/False
The following questions are all true/false questions.
Please Mark [a] on your Scantron sheet for true and [b] for false.
1) True or False? All objects have a center of mass.
2) True or False? The area under a velocity vs. time graph is the acceleration.
3) True or False? A ball is thrown up in the air and falls back to the level ground 10 sec. later. It reached
its highest height at 5 sec.
4) True or False? If a bullet is fired from level ground at an angle of 35◦ above the horizontal, its initial
velocity and final (“impact”) velocity are equal.
5) True or False? To three significant figures 0.00906499m is 9.06 × 10−2 m.
Multiple Choice
The following questions are multiple choice.
Please mark the best choice on your Scantron sheet.
6) The velocity function of a particle is v(t) = 3kt3 . What are the units of k?
(a)
m
s
(c) m
2
(b) ms
(d)
m
s4
~ =?
~ is 5.12km west, and vector B
~ is 4.31km north, and C
~ =A
~ − B,
~ then C
7) If vector A
(a) 0.81km
(c) 6.69km
(b) 2.76km
(d) 9.43km
8) An inclined plane makes an angle of 37◦ with the ground. What is the acceleration due to gravity a block
would feel along the inclined plane?
(a) 4.38 sm2
(c) 7.38 sm2
(b) 5.90 sm2
(d) 7.83 sm2
9) On a graph of velocity vs. time, the motion of an object with a constant acceleration of 2 sm2 would appear
as which?
(a) an upward-sloping straight line.
(c) an upward-cupped curve.
(b) a horizontal line.
(d) a downward-sloping straight line.
10) The adjacent graph describes the acceleration of a
particle that starts at rest @ t = 0s. What is that
particle’s velocity @ t = 10.0s?
a(m/s2)
6
(a) 23.0 m
s
(b) 25.5 m
s
(d)
t(s)
0
(c) 27.0 m
s
2
31.5 m
s
-6
4
6
8
10
11) Vector Transformations
(a) Bob throws a ball with a speed of 15.5 m/s at an angle of 25.0 degrees from the vertical. Draw a
diagram, select x and y axes, and convert the polar vector for the ball to a Cartesian vector.
(b) Alice skates on an ice rink with a velocity of (−5.25, 2.75) m/s. Convert this to a polar vector.
12) Tom fires a canon ball at an angle of 40.6 degree from the horizontal with a speed of 23.5 m/s. Tom’s
cannon is standing 27.0 m in front of a building whose flat roof is 4.75 m above the ground. Calculate
the horizontal distance from Tom at which the ball hits the roof.