Physics 101-01
Exam #1
San Francisco State University
(green & yellow)
Fall 2006
Instructor: Koskelo
General Instructions:
· This is a closed book test. However, you may use a calculator.
· All the formulas you need are on the formula sheet. Feel free to detach this.
· Once you have opened the test, you may not leave the room until you turn it in.
· No partial credit will be given. You should turn in only your scantron.
· Unless otherwise noted, please use g=10 m/s2.
Good luck!
1.) The speed of 22 miles per hour is most nearly the same speed as which of the following?
(Note: 1 mile = 1609 meters).
a.) 2 m/s
b.) 10 m/s
c.) 22 m/s
d.) 110 m/s
e.)1000 m/s
Questions #2-5 refer to the following:
A cannonball is shot upwards at 110 m/s, reaches the top of its flight, then hits the branch of a tall
tree on the way down, two seconds after that.
2.) How fast is the ball going one second after being thrown?
a.) 10 m/s
b.) 90 m/s
c.) 100 m/s
d.) 110 m/s
e.) 130 m/s
3.) How long does it take for the ball to reach the top of its flight (from when it was thrown)?
a.) 5 s
b.) 10 s
c.) 11 s
d.) 55 s
e.) 110 s
4.) When the ball is at the top of its flight, how far is it above where it was thrown?
a.) 10 m
b.) 55 m
c.) 110 m
d.) 605 m
e.) 1210 m
5.) How fast is the ball going just before hitting the tree?
a.) 10 m/s
b.) 20 m/s
c.) 100 m/s
d.) 110 m/s
e.) 120 m/s
Questions #6-9 refer to the following:
Marvin horizontally pushes on a 2 kg suitcase, so that it moves at constant speed in a straight line
across the floor.
6.) The force of gravity acting on the suitcase is:
a.) 0 N
b.) 10 N
c.) 20 N
d.) 200 N
e.) 980 N
7.) What is the net force on the suitcase?
a.) 0 N
b.) 10 N
c.) 20 N
e.) 980 N
d.) 200 N
8.) How many forces are acting on the suitcase in this situation?
a.) 0
b.) 1
c.) 2
d.) 3
e.) 4
9.) Which is the complete and correct explanation for why the suitcase has this particular motion?
a.) Because Marvin exerts a pushing force on the suitcase which is horizontal.
b.) Because this is a frictionless floor.
c.) Because of Newton’s 3rd Law.
d.) Because Marvin pushes with a force equal to the friction force from the floor.
e.) Because objects always move at constant speed.
Questions #10-11 refer to the following:
The velocity profiles for two trips (A and B) are shown below. The time between each velocity
shown is two seconds. (You may also assume nothing unexpected happens between the times
shown.)
trip A: 1 m/s, 2 m/s, 4 m/s, 6 m/s, 8 m/s, 11 m/s
trip B: 1 m/s, 3 m/s, 5 m/s, 7 m/s, 9 m/s, 11 m/s
19.) If Anne slows down by 3 m/s during this collision, this must mean Betty speeds up:
a.) by this same amount of 3 m/s.
b.) more than 3 m/s
c.) less than 3 m/s
d.) Betty does not need to speed up at all.
e.) Not enough info.
Questions #20-21 refer to the following:
Two balls are thrown off a cliff. Ball A is thrown vertically upward at 40 m/s, and ball B is
thrown vertically downward at 20 m/s.
20.) Which ball will reach the ground first?
a.) A b.) B c.) Neither; they will land at the same time.
21.) Which ball will hit the ground with a larger speed?
a.) A b.) B c.) Neither; they will hit with the same speed
d.) Not enough info.
.
d.) Not enough info.
22.) When you visit another planet, which of these quantities may change?
I.) your weight
II.) the force of gravity pulling on you
III.) your mass
a.) I only
b.) II only
c.) III only
d.) I and II
e.) II and III