Download Review Sheet with Answers

unit review answers.notebook
November 24, 2015
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Review Unit 8: Forces
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In the picture below, a girl is sitting on a swing. What is the net force on the girl?
A
0 N
B
245 Newtons upwards
C
490 Newtons upwards
D
490 Newtons downwards
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As a box is sliding down a ramp , a 10 N force of gravity is pulling the box down the ramp while a 2 N force of friction acts to stop the box. What is the net force accelerting the box down the ramp?
Subject: Physical Science
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A 0.015 kg baseball and a 7.25 kg bowling ball are both rolling along at 3 m/s. Which one is easier to stop and why?
A
The bowling ball becasue it has less inertia
B
The baseball because it has more inertia
C
The bowling ball becasue heavy objects are naturally prone to stop on their own
D
The baseball because it has less inertia
A rocket can fly into space because:
A
the hot exhause gases hit the air and create a vacuum behind the rocket
B
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A
5 N
B
8 N
C
10 N
D
12 N
If the forces are balanced on an object, which of the following could the object do?
A
turn
the rocket pushes the exhaust gases backward, and there is an an equal and opposite reaction pusing the rocket forward
B
speed up
C
slow down
maintain constant speed
C
The launch pad pushes the rocket forward like a slingshot
D
D
when the gases are burning up, the mass of the rocket decreases, changing the amount of gravity on the rocket
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unit review answers.notebook
6
Newton's first law of motion is also called the law of ___
A
Mass
B
Force
C
Inertia
D
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November 24, 2015
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Constant Velocity
The relationship among mass, force, and acceleration is explained by? 9
Which of the following is not an example of unbalanced forces acting on an object?
A
an acorn falling from a tree
B
a car moving at a constant speed of 55 mph
C
a motorcycle change speed from 50 mph to 70 mph
D
a truck slowing down as it approaches a red light
A feather will fall through the air more slowly than a brick because of? A
conservation of momentum
A
air resistance B
Newton's first law of Motion
B
gravity
C
Newton's 2nd law of Motion
C
inertia
D
Newton's 3rd law of Motion
D
momentum
10 For an object of a given mass, the greater the force that's applied to it, the greater its ___ wil be.
11 The statement "to every action there is an equal and opposite reaction" is
A
velocity
A
the law of conservation of momentum
B
gravity
B
Newton's first law of motion
C
acceleration
C
Newton's 2nd law of motion
D
inertia
D
Newton's 3rd law of motion
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unit review answers.notebook
12 Calculate the force on an object that has a mass of 12 kg and an acceleration of 4 m/s2
November 24, 2015
13 A 300 N force acts on a 25 kg object. The acceleration of the object is?
A
3 N
A
7,500 m/s2
B
0.3 N
B
300 m/s2
C
48 N
C
25 m/s2
D
8 N D
12 m/s2
14 Objects tend to resist changes in motion. This property is called:
15. Which object has more inertia? A. Train or a car A
weight
B
momentum
C
density
D
inertia
B. A ping pong ball or a baseball
C. A fast bowling ball or a slow bowling ball
*Must correctly answer all 3
16. Are the forces balanced or unbalanced?
A. A person sitting on a chair balanced
B. 20 N left and 30 N right unbalanced
C. An object at constant speed balanced
D. An accelerating plane unbalanced
E. A stopping car unbalanced
17. Calculate the net force and the acceleration of the object.
Net Force: 21 N ­­>
Acceleration: 7 m/s2
*must correctly answer all 5
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unit review answers.notebook
18. What is the difference between mass and weight?
Which changes in space?
November 24, 2015
19. If you increase an objects mass, will it accelerate faster or slower?
slower
Mass is the amount of matter in an object, and weight is the force of gravity acting on the mass. Weight changes in space due to a change in gravity.
20. Which of Newton's Laws applies:
21. Which of Newton's Laws applies:
When you put a book on a table gravity pulls down on the book and the table pushes up on the book.
3rd Law
A person is pushed forward into their seatbelt when a car stops.
22. Which of Newton's Laws applies:
A larger car takes more force to move.
2nd Law
1st Law
23. Which of Newton's Laws applies:
A person leans on a wall and the wall pushes back.
3rd Law
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unit review answers.notebook
24. Which of Newton's Laws is represented by this diagram?
November 24, 2015
25. Which of Newton's Laws applies:
An inflated balloon releases air and moves horizontally. 2nd Law
F=ma
3rd Law
26. If you increase the force on an object, will it accelerate faster or slower?
27. In the absence of air resistance what would fall faster, an elephant or a toy doll?
faster
neither, they will fall at the same rate
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