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Physics Midterm Review 2014-2015
The third part of the midterm/common assessment consists of the 50 multiple choice questions on
topics have studied so far: conceptual, math.
MOTION: Chapters 2 and 3
How do you know if object moving? (relative motion)
Representing motion through motion diagrams, dot diagrams, graphs
Distance travelled, displacement, speed and velocity, acceleration.
What type of motion is shown by a particular graph?
Using kinematic equations for problem solving:
Constant velocity
Accelerated motion in general, and free fall where accel = ‘g’
DYNAMICS Chapter 4, Chapter 5 section 2
What is a force?
Difference between contact force and field force
variety of forces: tension in rope, gravity, friction, push or pull, air drag, etc.
Free body diagrams, aka force diagrams
Newton’s Three laws of Motion
First law: force causes a change in motion,
concept of inertia, mass
Second law: F net = ma
Concept of Fnet = 0 , zero acceleration
Object at rest OR
Object moving at constant velocity, example: terminal velocity
Concept of Fnet = ma
Problem solving with more than one force
Difference between mass and weight Fg = mg
Third law: identify forces pairs, action and reaction
Force due to friction and coefficient of friction, static and kinetic friction
PROJECTILE MOTION Chapter 6 section 1
Understand relation between horizontal and vertical motions.
Solve horizontally-launched problems.
Know concepts of velocity and angle of launch (greatest range, etc.)
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CIRCULAR MOTION AND GRAVITATION Chapter 6 section 2
What is uniform circular motion?
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Variety of forces can cause circular motion: all can be called centripetal forces
Understand/ calc centripetal accel and centrip force
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Nature of Science
Scientific Notation
Metric units (You should know the standard units for all of the physical quantities
on this sheet!)
Vector vs. Scalar
Physics Midterm Review 2014-2015
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Graphs
You should look over old tests, labs, homework, and study guides. Questions on this study guide
are not meant to be all-inclusive or 100% representational of the midterm exam; it is merely a
guide.
Kinematics
Make sure you know how to:
a) Draw a motion diagram for a moving object
b) Determine the direction of acceleration using a motion diagram.
c) Interpret d vs t and v vs t graphs in terms of position, velocity,
displacement, and acceleration.
d) Know definitions of key terms and understand situations when velocity
and acceleration might be negative, positive or zero.
1. What is the difference between initial position, final position,
displacement, and path length?
2. The position-vs-time graph for a moving object is a straight line with a slope
equal to -15.0 m/s and starts at d = 3. Explain what this means about the
motion of the object.
3. Give an example in which an object has negative acceleration and is
speeding up. Give an example in which an object with positive
acceleration is slowing down. Be able to draw graphs and motion
diagrams for each.
4. A car’s motion is described by the following function:
d(t) = (-2)t2 + (12)t + (-48 )
What is the car’s position and velocity at time zero?
What is its acceleration?
At what time (if any) does the car’s velocity become zero?
Physics Midterm Review 2014-2015
5. While driving along a flat stretch on the highway, there is a policeman
parked behind a bush. As you drive by he uses his speed gun to track your
speed over a period of 10 seconds. The data he includes in his report is
given in the table below.
Time (s)
0
2
4
6
8
10
Velocity
(mph)
45
60
78
94
108
125
a) Plot a velocity vs time graph.
b) What type of relationship does the graph
show?
c) What is the equation of the graph?
d) Using the graph, determine the displacement
of the car after 8 seconds.
6. A car goes from rest to 100 km/hr in 10 seconds. It then travels at that rate
for the following hour. After that hour, it brakes to a stop in 15 seconds.
a) What is the car's acceleration during the 1st 10 seconds?
b) What is the car’s acceleration during the last 15 seconds?
c) What is the total distance (in meters) that the car travels during
the trip: speeding up, constant velocity and slowing down?
d) What is the car's average velocity during the whole trip?
Physics Midterm Review 2014-2015
7. If you throw a tennis ball straight up in the air with a velocity of 30m/s, how
long will it take to come back to the ground?
What is the acceleration of the ball at the maximum height of the flight?
8. Ashleigh and Rachael are bored with attending choral lessons inside the
high school and decide instead to practice their singing while skydiving.
They pick their new favorite song, Ring of Fire by Johnny Cash, and get into
the airplane. Ignore air resistance.
a) Draw a motion diagram and a separate force diagram while they are
falling before deploying the parachute.
b) If Ring of Fire is 2 min 36 sec long, at what altitude do they have to fall
from in order to finish the song right before they deploy the
parachutes?
d) What will their final velocity be right before deploying the parachutes?
9. Kelsey is playing in a lacrosse game against North’s rival South. She
catches a pass and has a breakaway past the defense. Her initial speed is
2 m/s and she accelerates at a rate of 4 m/s2 for 3.4 s until she shoots the
ball.
a) Draw a motion diagram
b) How fast is she going when she releases the ball?
Physics Midterm Review 2014-2015
c) How far did she run while accelerating?
Forces and Newton’s Laws
Make sure you know how to:
a) Draw a force diagram, and use the force diagram to apply Newton’s
second law.
b) connect descriptions of motion, motion diagrams and motion graphs with
Newton’s concepts.
c) Understand and apply Newton’s First, Second, and Third Laws to word
problems.
d) Understand static and kinetic friction, force of friction and coefficients
10. You slide toward the right at decreasing speed on a horizontal wooden
floor. What objects that interact with and exert forces on you?
11. Why do you need to keep pushing a grocery cart in a store in order to
keep it moving? Doesn’t this go against Newton’s 1st Law?
12. An elevator in a tall office building moves downward at constant speed.
How does the magnitude of the upward force exerted by the cable on the
elevator compare to the magnitude of the downward force exerted by
Earth on the elevator? Explain your reasoning.
13. Three friends are arguing about the type of information a bathroom scale
reports. Eugenia says that it reads the weight of a person, Alan says that it
reads the sum of the forces exerted on the person by Earth and the scale,
and Mike says that the scale reads the force that the scale exerts on the
person. Who do you think is correct? Why?
Physics Midterm Review 2014-2015
14. Identify third law force pairs for the following interactions: A rollerblader
and the floor, a volleyball player and the volleyball, and a speeding up
car’s tires and the road.
15. Draw all of the forces for the following rocks.
no acceleration moving at constant speed
moving in a circle around post
16. Alex’s car (900 kg) stalls 10 m from the Amwell Road parking lot. Alex gets
two of his strong physics friends, Sam and Tim, to help him move the car.
The 3 students push horizontally with a force of 500 N each.
a. Sketch the situation, circle the object of interest
b. Draw and label a force diagram for the object of interest
c. Solve for any of the forces that you can.
d. What is the acceleration of the car?
e. How long does it take them to reach the parking lot?
17. You are pulling a sled on snow with your cousin on it. Together the mass is
40 kg. The coefficients of static and kinetic friction are 0.30 and 0.20.
Physics Midterm Review 2014-2015
a. How hard do you have to pull to just get them moving?
b. How hard would you have to pull to keep them moving at a
constant velocity?
c. You pull with a force that’s 10 N higher than your answer to partb.
What is the resulting acceleration?
d. Now you are pulling on a slippery section of snow and ice. If you
have to pull with 60N to keep moving at a constant velocity, what is
the coefficient of friction?
Two Dimensional Motion
Make sure you know
 What information or data determines the time in the air,
 which component of velocity is constant,
 and which component of velocity is accelerating.
 How to determine the components of a velocity vector
18. Michelle stands on the Millstone River Bridge kicking stones into the water
below.
a. If Michelle kicks a stone with a horizontal velocity of 3.50 m/s, and it
lands in the water with a horizontal distance of 5.40 m from where
Michelle is standing, what is the height of the bridge?
b. If the stone had been kicked harder, how would this affect the time
it would take to fall?
19. A pumpkin is launched out of a cannon at an angle of 30 degrees with an
initial velocity of 50 m/s.
Physics Midterm Review 2014-2015
a. What is the horizontal velocity? (horizontal component)
b. What is the initial vertical velocity? (vertical component)
20. A boy on a 250 m high tower throws a ball that lands 100 m away in the
horizontal direction.
a) How long (in seconds) does the ball take to hit the ground?
b) What was the ball’s initial velocity?
Circular Motionuse your understanding of Newton’s laws to explain why
you tend to slide across the car seat when the car makes a sharp turn.
21. A 13 g holiday ornament is attached to a 0.93 m string. The stopper is
swung in a horizontal circle making one revolution in 1.18 s.
a. What is the linear/tangential speed of the ornament?
b. Determine the force exerted by the string on the ornament.
c. In what direction will it go if you let it go (besides down)?
22. A 5 kg metal ball is swung in a circle attached to a 1 meter chain. The ball
is traveling at 5 m/s.
a. Determine the centripetal acceleration of the ball
b. Determine how hard you need to pull on the chain to maintain this
rotation.