Physics 1401
Exam No. 1
Physics 1401 Test I
Name______________________
Instructions: Show ALL of your work for partial credit. Have a good time? Best of luck.
Multiple Choice (5 points each)
1.) Add two vectors together: A has a magnitude of 5m and is at 300 from the x axis
0
while B has a magnitude of 10m and is at 110 from the x axis. The Resultant is about:
a.) 14m long at an angle of 54o
b.) 14m long at an angle of 5.5o
c.) 12m long at an angle of 54o
d.) 12m long at an angle of 86o
2.) An object moving in a straight line with an initial velocity of 12 m/s is found to be
moving at 48 m/s after traveling a distance of 75 m. What was its acceleration in m/s2 ?
a.) 2.9
b.) 7.5
c.) 11.1
d.) 14.4
e.) 5.7
3.) A certain physical quantity, R, is calculated using the formula: R = 4a2(b – c) where a, b,
and c are distances. What is the SI unit for R?
a) cm
b) cm2
c) m
d) m2
e) m3
4.) A diver launches off of a 25m cliff with a speed of 5m/s and an angle of 300 from the
horizontal. How long does it take the diver to hit the water?
a.) 1.2s
b.) 2.53s
c.) 3s
d.) 3.57s
e.) 4.27s
5.) You drop a ball out of a 2nd story window. The ball strikes the ground 3 seconds
later. About how high above the ground is the window?
a.) 36 m
b.) 44 m
c.) 88 m
d.) 33 m
e.) 27 m
6.) Which is a version of Newton’s 1st Law of Motion?
a.) The sum of forces is proportional to the acceleration
b.) An object at rest tends to remain at rest unless acted on by a force
c.) For every action there is an equal but opposite reaction
d.) F = ma
e.) Without external forces the Energy is conserved.
7.) A ball is thrown straight upward at 28.0 m/s initially. What maximum altitude does it
reach in meters?
a.) 9.6
b.) 10.0
c.) 27.4
d.) 40
e.) 54
8.) You accelerate from 14m/s to a speed of 25m/s in order to get onto the freeway. If
you are given a ramp 100 meters long to get up to speed, what will your acceleration be?
a.) 1G
Note: 1G = 9.8m/s2
b.) 3G
c.) 0.22G
d.) 0.53G
9.) Convert 60 mi/hr to m/s (1 mi = 1.609 km):
a.) 96.54 m/s
b.) 37.29 m/s
c.) 38.27 m/s
d.) 26.82 m/s
10.) A girl is using a rope to pull a box that weighs 300 N across a level surface with
constant acceleration. The rope makes an angle of 30 above the horizontal and the
tension in the rope is 100 N. There is no friction present. What is the normal force of
the floor on the box?
a.) 300 N
b.) 86 N
c.) 50 N
d.) 250 N
e.) 400 N
Short Answer (10 points each)
11.) Since Force is defined by Newton’s 1st law and acceleration is defined
mathematically, show how Newton’s second law (F = ma) can be used to explain what
mass (also called inertia) is.
12.) State Newton’s 3rd Law of Motion.
Show All Work (10 points each)
13. M1 = 20kg and M2 = 10kg. The Pully (a) is massless
a.) Draw all necessary Free Body Diagrams.
b.) Find the common acceleration of the two masses.
c.) Find the tension in the string.
14.) M1 = 10kg in both parts.
a.) s = 0.2, Find the maximum value of M2 that would allow the system to
remain at rest.
b.) k = 0.15 and M1 starts off is moving to the right. Find the acceleration of the
system if M2 = 30kg.
15.) A car is at rest at a traffic light when the light turns green. At the moment that the
car starts accelerating with an acceleration of 2.5 m/s2 a truck passes by moving at a
constant speed of 11.11 m/s.
a.) How far from the light will the car catch up to the truck?
b.) How fast will the car be going when it passes the truck?