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South Pasadena  Physics
Mid Term
Name____________________ Period___
Practice Test

1About
Science
True/False
____ 1.Physics is the most basic of all the sciences.
____ 2.Science deals with practical problems while technology deals with theoretical questions.
____ 3.Theories must always be modified as new evidence is gathered.
____ 4.Scientific Claims made by scientists must be able to be proven wrong.
Matching:
5. Theory
____
(a) A statement that is not immutable or absolute.
6. Hypothesis
____
(b) Something that envelops the overriding idea dealing with phenomena.
7. Fact
____
(c) Based on a synthesis of a large body of information.
8. Concept
____
(d) An educated guess regarding the behavior of some phenomenon.
9. Convert the number 70 years into seconds and express the answer as a power of 10.
____________
10. How many significant figures does the number 15.00 have?
____________
11. Forty kilometers is equivalent to how many meters?
____________
12. Fifty milligrams is how many micrograms?
____________
13. What is the product of 13.95 cm and 2.83 cm written to the proper number of significant digits?
(Hint: remember that you round off to the least number of significant digits in the numbers used)
a) 39
b) 39.5
2 
14.
c) 39.48
Linear
distance traveled from rest =½at2
Fill in the missing information:
d) 39.479
____________
Motion
acceleration =(vf-vi)/t
Speed (km/hr)
Distance (km)
Time (hours)
?
350
5.15
95
?
.035
15.
A car starting from rest moves with constant acceleration of 2.0 m/s2 for 10 s, then travels with constant speed
for another 10 s, and then finally slows to a stop with constant acceleration of – 2.0 m/s2.
How far does it travel?
16.
If you try to catch a ruler to measure your reaction time and the ruler falls 5.0 cm, what is your reaction time?
17.
An apple is thrown upward into the air with an initial speed of 30 m/s.
a) How fast is it going after 2.0 seconds?
__________
b) What is its acceleration after 3.0 seconds?
__________
c) What is the initial velocity of the apple when it is thrown upward?
__________
18.
If an apple falls from the balcony of a tall building, how far will if travel in 3.0 seconds? __________
19.
When a car is turning a corner, is it accelerating? yes or no
__________
Why or why not?
_______________________________________________________________
20.
Sketch a distance vs. time graph and a speed vs. time graph for ball being dropped off the science balcony.
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Distance |
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time
21.
Speed
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time
Describe in words, the motion of the falling ball in terms of distance and speed and acceleration over time:
______________________________________________________________________________________
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3  Projectile
22.
23.
24.
Motion
Label the following as either Vector quantities or Scalar quantities.
Treasure map _____
Velocity
_____
Your shoe size _____
Speed
_____
Your weight
_____
Force
_____
Acceleration _____
S.S #
_____
What is the resultant of two vectors, X & Y at right angles to each other, whose
magnitudes are 60 km/hr and 80 km/hr? Sketch the vector diagram
________
A projectile is launched horizontally from the science balcony with an initial horizontal velocity of 15 m/s.
The height of the balcony is 6.0 meters high. How far away horizontally does the projectile land? ________
25.
If a blow dart is shot thru a blow dart gun and travels 12.0 meters away and falls a vertical distance of 4.0
centimeters. What was the initial velocity of the dart in meters/second?
________
26.
What is the acceleration of the dart in the horizontal direction?
________
27.
What is the acceleration of the dart in the vertical direction?
________
28.
If the blow dart was shot upward at an angle of 35° at what other angle could
the dart be shot so that it would travel the same horizontal distance?
________
A bullet is fired horizontally across a field, from a gun, while another identical bullet is
dropped to the ground from the same height as the gun at the instant the bullet is fired.
Do both bullets hit the ground at the same time?
________
29.
Why or Why Not?
__________________________________________________________________________________
__________________________________________________________________________________
4Newton’s 1
s t
Law of
Motion-Inertia
30.
Which has greater inertia: a 2 kilogram mass or a 4 kilogram mass?
31.
You are in outer space and you throw the 2 kilogram mass away from your spacecraft;
describe the motion of the object. It will travel in a _____________ direction and with a constant
______________.
32.
What is the weight of the 2 kilogram object in Newtons?
33.
If your mass is 60 kilograms and you weigh 120 pounds,
34.
________
________
a) what would be your mass on the moon?
________
b) what would be your weight on the moon?
________
If object A is 2.0 N on the earth and another object B is 2.0 N on the moon,
which one has a greater mass?
________
35.
A heavy mass is attached to a string and hung from a horizontal bar and then a second string
is attached to the lower end of the mass and is dangling below the mass. The mass has inertia.
If you want the bottom string to break when you pull on it, should you pull the string
slowly or with a sudden jerk?
_______________
36.
If you wanted to easily pass a sharp knife thru a raw potato, should you . .
______
a) place knife vertically on table, place potato on top and then pound bottom of knife to table or
b) place potato on table and jab the knife through the potato
37.
If you are standing on a moving bus and you drop a coin to the floor, how will the coin fall? ______
a) It will fall directly down in a straight line to your feet, because of the coin’s inertia.
b) It will fall to the ground farther away from your body than where it started, because of inertia.
5
Newton’s 2
n d
Law- Force, mass & Acceleration
38. If a 4.0 kilogram mass is accelerated at a rate of 3.0 m/s2, what net force
must be causing the acceleration?
________
39. If a net force of 24 Newtons is accelerating a mass at 4.0 m/s2, what is the value of the mass?
________
40. If a 2.0 kg cart is being pulled with a force of 8.0 Newtons against a frictional force of
2.0 Newtons, what the acceleration of the cart?
(Draw a Free Body Diagram below:)
41
________
An 85 kg skydiver is falling through the air. The air is exerting 250 Newtons of air resistance.
What is the acceleration of the skydiver?
(Draw a Free Body Diagram below:)
________
42. The force of gravity acting on an elephant, compared to the force of gravity acting on a feather is
a) greater for the elephant
b) greater for the feather
c) the two are equal since the acceleration of the two is the same
_____
43. The reason the two objects above have the same value for their accelerations in a vacuum is because . .
a) as mass increases, the force of gravity acting increases proportionally the same amount.
b) as mass increases, the force of gravity acting decreases proportionally the same amount.
c) their accelerations are the same in a vacuum only if their masses are identical.
6
Newton’s 3
r d
Law of Motion-Action
_____
& Reaction
44. If a father and young son are on a frictionless ice pond with a rope between them and they
both pull on the ends of the rope, the amount of force exerted by the father on the son will be . . ?
a) greater than the force exerted by the son
b) less than the force exerted by the son
c) equal to the force exerted by the son
_____
45. If the father has a mass of 80 kg and the son has a mass of 40 kg, how will their accelerations compare?
a) The acceleration of the father will be twice as great.
b) The acceleration of the son will be twice as great.
c) They will both have the same acceleration.
_____
46. When a balloon filled with air is released through the air, it will fly all over the place. If the action force is the
rubber balloon pushing on the molecules of air in the balloon, then the reaction force is . . .
a) The air molecules outside the balloon pushing back on the rubber balloon.
b) The air molecules inside the balloon pushing back on the balloon.
c) The rubber balloon pushing on the air molecules outside the balloon.
47. Consider a horse pulling a carriage along the road by exerting a force on the carriage.
_____
_____
a) The reaction force acting on the horse cancels the action force by the horse.
b) The reaction force acting on the horse is opposite in direction but not equal
in magnitude to the action force by the horse.
c) The reaction force is acting on the same object as the action force.
d) The reaction force is acting on a different object and is equal in magnitude to the action force.
48. When a bug smashes into a windshield on a moving car, the car must be affected in speed by the bug,
according to Newton’s Third Law of Motion.
(circle correct answer)
True or False
49. A spring scale is suspended horizontally between two equal weights of 50 Newtons, each hanging over a
pulley and hanging downward over the two ends of the table. The reading on the scale must be . . .
a) 0 Newtons
b) 50 Newtons
c) 100 Newtons
7 
Momentum
Elastic Collisions:
Inelastic Collisions:
Explosions:
_____
p=mv,
Ft =Δp = mΔv
m1v1 + m2v2 = m1v1 + m2v2
m1v1 + m2v2 = (m1 + m2) v2
(m1+ m2) v1 = m1v1 + m2v
50. Which object has a greater momentum? A 1200 kg car moving at 10 miles per hour
or an 800 kg car moving at 25 miles per hour?
51. If the momentum of a soccer ball is 12 N-s and it is moving at 6.0 m/s,
what is the mass of the soccer ball?
_____
________
52. A 55 kg person jumps off a chair and is moving at 3.0 m/s before making contact with the floor.
How much impulse did the floor exert on the person if the person required 1.0 second to come to rest?
________
53. How much force in Newtons did the person experience in coming to rest?
________
54. If the person had come to rest in 0.01 seconds by landing with stiff legs, how much force
would the person experience on the landing?
________
55. An inelastic collision occurs between two automobiles, “a” and “b” whose masses are 1200 kg and 800 kg
respectively. If car “a” had been moving at 40 m/s and car “b” was at rest, what is the velocity
of the two entangled cars after collision?
________
56. If car “b” above had been moving towards car “a” at 25 m/s, what would be the velocity
of the two cars after collision?
________
57. At a fireworks display, a firework has a momentum of 25 N-s when moving northward
into the air before it explodes. After the explosion, two of the three pieces are moving
southward with a combined momentum of 15 N-s. What is the momentum of the third piece?
________
(Draw a diagram to help you solve this problem.)
8 
Energy
Work = F x d ,
P o we r =W /t i me ,
P .E.
=
mg h ,
K.E. =½ mv
2
58. If you turn on the radio in your car with the engine off, will more gasoline be burned later when
the car engine is turned on, as a result of having turned on the radio? Yes or No
59. If you do 8.0 joules of work in lifting your 2.0 kg physics book, how high in centimeters
did you lift your book?
________
60. If you lifted your book by expending 16.0 watts of power, how many seconds was required
to lift the book?
________
61. How many joules of potential energy does your 2.0 kg physics book have while sitting
on your desk which is 80 centimeters above the ground?
________
62. If your physics book fell off of your desk, what velocity would it have before hitting the floor?
________
63. A bowling ball hanging from the ceiling is brought back to a point where it has 85 joules
of potential energy. After being released, it has 25 joules of potential energy at a certain point.
How many joules of kinetic energy does it have at this point?
________
64. A lever is used to lift an 80 Newton object to a height of 1.0 m. If you exerted an input force
of 20 Newtons, through how much distance did you move the lever?
________
65. What is the mechanical advantage of this lever?
________
66. How much work must be done to stop a 1000 kg car traveling at 31 m/s?
________
67. An oxygen molecule of mass 5.31 x 10-26 kg has a kinetic energy of
6.21 x 10-21 Joules. How fast is it moving?
________
9

C i r c ul a r
M oti o n
68. A bug is crawling on the record of a record player near the axis of rotation.
An ant is also crawling near the outer edge of the record. If the record player is turned on,
which one experiences a greater linear velocity?
Which one is experiencing the greater angular velocity?
_______
_______
69. If the bug is at a radius of 2.0 cm (0.020 m) from the axis of rotation, and the period of
rotation of the record (time for one rotation) is 2.0 seconds, what is the linear velocity
of the bug? (linear velocity = 2πr/T)
_______
70. If the bug has a mass of 15 grams (0.015 kg) and is at a radius of 2.0 cm (0.020 m) from
the axis of rotation, what is the centripetal acceleration of the bug? (ac=v2/r)
_______
71. What centripetal force (in Newtons) is acting on the bug as it is rotating?
(Fc =mac=mv2/r)
_______
72. When you are a passenger in a car and the car is turning right on a turn, in which direction
do you feel being pulled or pushed?
_______
73. Is this push or pull that you feel, a centripetal or centrifugal force?
_______
74. Explain to your partner, what is the cause of the force that you feel on the turn!
75. What is the gravitational force of attraction between the Earth and the moon whose masses
are 5.97 x 10 24 kg and 7.35 x 10 22 kg, respectively and the distance between the Earth and
the moon is 384 x 10 6 m? The universal gravitational constant, G, is 6.67 x 10-11 N-m2/kg2.
______________