Download Sample Test Questions

Engineering Physics I
Sample Test Questions
Instructions.
 Exam credit is based on your individual work and explanations in your own words. The answer
alone may be worth nothing. Reciting work and words from another source, e.g. your textbook, a
website, etc., is never an acceptable answer and will likely receive little or no credit.

Final answers and units must be clearly indicated by boxing, circling, or underlining.

Unnecessary and/or incorrect work subtracts from correct work.

Writing that is hard to read, e.g. written smaller than the font used on this page, lightly written,
messy, etc, will receive little or no credit.

The instructor/proctor will not comment on your work during the examination.

Assume that all numbers are known to 3 significant figures, e.g. 5 meters = 5.00 meters.
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All for-credit work must be written on the exam, no attachments are allowed.

Point values are written in [brackets] at the beginning of a question.
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One (1) 3”x5” note-card f/b is allowed on each mid-term exam.

Scientific/graphing calculators are allowed.

Display or use of a cell phone or wireless device results in a score of zero for the exam.
g = 9.8 m/s/s
1 mile = 1609m
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1 hour = 3600s
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1. [3] Two forces F1  100 N @ 0 and F2  100 N @ 30 act on an object. Calculate the magnitude
 
 
F1  F2 and direction of F1  F2 . All angles are measured counter-clockwise from the +x axis.
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2. A box weighing 100N is hanging in
equilibrium as shown.
a) [1] Write down the x and y equations for
equilibrium of the point where the three ropes
are joined in terms of T1 , T2 , T3 , the angles
shown in the diagram, and the x,y axis
directions shown.
Answer part a) below:
b) [2] Calculate the magnitude of the tension force T2 .
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3. A horizontal force is applied to a 40kg block as
shown. The 40kg block is on a horizontal
frictionless surface. There is sufficient friction
between the 10kg and 40kg block to allow the
10kg block to move with the 40kg block with no
slipping.
Part a) force diagram:
a) [3] Draw a force diagram for the 10kg block
using the circle to the right to represent the 10kg
block. Label each force clearly as done in class.
Use / symbols to indicate any equal magnitude
forces and x symbols to indicate any Newton’s 3rd
Law pairs.
b) [1] Calculate the acceleration of the 40kg block.
c) [2] Calculate the magnitude of the frictional force acting on the 10kg block.
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4. A 10kg box is sliding up a rough plane inclined 25 degrees from horizontal. The coefficient of kinetic
friction of the box with the plane is 0.30. When the box is at y = 0m, it is moving at 5m/s. The box
continues sliding up the incline until it stops.
a) [3] Fill in each empty spot in the table with a calculation and calculated value of energy in joules. If a
value is zero, you may simply enter “0”.
Type of
Energy
mgy
1
2
mv 2
1
2
kx2
A (at y = 0m )
B (at highest point up incline)
0
k Fn d
Totals
b) [2] Calculate the height y when the box first comes to rest.
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5. [2] The position of an object as a function of time is x(t) = 3 – t + 5t2, where x is in meters and t is in
seconds. Calculate the velocity of the object at time t = 2s.
6. [1] The graph shows the velocity of a particle as a function of time. Calculate the distance the
particle moves from 0 to 8 seconds.
8. [1] A car is moving due East while a force acts due West on the car. Does this force do positive,
negative, or zero work on the car? ____________ Explain for credit.
9. [1] An elevator weighing 10,000N is moving upward at a constant velocity of 2m/s.
Calculate the power required to maintain this constant upward velocity.
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1. [2] Identical projectiles are fired with the same speed from the same height above flat level
ground in two different ways: One is fired horizontally. The other is fired at an angle below
horizontal. If air resistance is negligible, how does the speed of impact with the ground
compare for the two different firings? (check one statement) They both hit with the same
speed ____. The one fired horizontally hits at higher speed ____. The one fired below
horizontal hits at higher speed ____. Explain your answer for credit.
2. A mass M is spun in a vertical circle of radius R with a strong light cord. If the speed of the
mass is V at the top of the circle, solve for the tension in the string at this position by applying
Newton 2nd Law.
3. [2] The initial and final momentum of an object is shown below. Use the given vectors to
draw the correct impulse vector received by the object. Drawing must be to scale shown.

p1i

p1 f
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4. [5] A 1000kg car moving at 10m/s collides elastically in one dimension with a 2000kg car at
rest. Assuming that no external forces act on the cars, how fast is the 2000kg car moving after
the collision?
5. Two masses are hung over a frictionless pulley with a strong light cord as shown below.
The pulley is a solid disk, mass = 5kg, and radius = 10cm. Mass m1 = 8kg and m2 = 12kg. The
masses are released from rest and the cord does not slip.
a) [1] Check the correct statement, then explain it.
___ The tension in the cord connected to m1 is larger than to m2.
___ The tension in the cord connected to m2 is larger than to m1.
___ The tensions in the cords are the same on each side.
For credit, explain your reasoning:
b) [5] Calculate the angular acceleration of the pulley after the masses are released.
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6. [5] A uniform ladder of length L = 4m is and mass M = 20kg is leaning against a frictionless
wall in equilibrium as shown below. Calculate the force the wall exerts on the ladder. Explain
your work in order to ensure maximum partial credit.
80
7. [2] A Merry-go-round, radius R = 2m, has a rotational inertia of 50 kgm^2 and is initially at
rest. A child mass = 35kg runs at speed = 4m/s as shown below and jumps onto the merry-goround. Calculate the rotational rate of the merry-go-round with the child onboard at the edge
of the merry-go-round.
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8. [3] A uniform rod 3 meters long is hung from one end about
a frictionless horizontal axis. The rod is pulled slightly to one
side and released. Calculate the period of the motion.
9. The position of an object is given by x = 0.12cos(8t), where x is in meters and t is in seconds.
a) [1] What is the amplitude of the motion in meters?
b) [1] What is the maximum speed of the object?
c) [1] What is the period of the motion?
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