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NEWTON'S LAWS

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					                           NEWTON’S LAWS
Friction - _______________________________________________________________

List the three types of friction. _____________________________________________

Give an example when friction is good. _____________________________________

_______________________________________________________________________

Give an example when friction is bad. _____________________________________

_______________________________________________________________________

Arrange the following pairs of surfaces in order of most friction to least friction:
   a. a shoe sole and a waxed basketball court           _____
   b. a shoe sole and the frozen surface of a lake       _____
   c. a shoe sole and the sidewalk                       _____


Gravity - ______________________________________________________________

Mass - ________________________________________________________________

Weight - _______________________________________________________________




NEWTON’S THREE LAWS OF MOTION

Newton’s First Law of Motion – An object at rest remains at rest until a force moves
it. An object in motion stays in motion until a force stops it.

What is another name for this first law? _________________________________

Give examples of this first law of motion.
Newton’s Second Law of Motion – F=ma

Make a triangle for Newton’s second law.




If you kicked a soccer ball and a bowling ball with the same force, which will have
the greater acceleration? Why?



Describe what would happen if you pushed an empty shopping cart and a full
shopping cart with the same amount of force.




Solve: Zookeepers lift a stretcher that holds a sedated lion. The total mass of the
lion and the stretcher is 175 kg, and the lion’s upward acceleration is 0.657 m/s 2.
What is the unbalanced force necessary to produce this acceleration of the lion and
the stretcher?




1. What is the net force necessary for a 1.6 x 103 kg automobile to accelerate
forward at 2.0 m/s2?

2. A baseball accelerates downward at 9.8 m/s 2. If the gravitational force acting on
the baseball is 1.4 N, what is the baseball’s mass?

3. A sailboat and its crew have a combined mass of 655 kg. If the sailboat
experiences an unbalanced force of 895 N pushing it forward, what is the sailboat’s
acceleration?

4. What is the acceleration of a boy on a skateboard if the unbalanced forward force
on the boy is 15 N? The total mass of the boy and the skateboard is 58 kg.

5. A brick is resting on a table. The mass is 2 kg. If the table is smooth and
frictionless and we pull on the attached string with a force of 12 N, what is the
acceleration of the brick?
6. If you are pulling with a force of 20 N on a brick, what is the mass of the birck if
you find that it accelerates at 4 m/s2?

7. A rocket ship is on the launch pad. What force will it take to give the rocket an
initial acceleration of 50 m/s2 if its mass is 50,000 kg?

8. A flying bird decides to swoop down on some prey. Its mass is 5 kg and it dives
with an initial downward acceleration of 15 m/s2. How much force must it exert
with its wings to attain this acceleration?


Newton’s Third Law of Motion – For every action there is an equal and opposite
reaction. Give examples.




What Law of Motion is being described?

   11. If you are sitting in the back of a pickup truck, you move
       backward when the truck accelerates.                             _________
   12. A straw can pierce a potato if the force and acceleration
       are great.                                                       _________
   13. A balloon moves forward when the air is released.                _________
   14. An egg will fall into a container when the support beneath
       it is removed.                                                   _________
   15. A kid bounces down on a trampoline.                              _________
   16. You shove a full shopping cart with a small force and it
       barely moves.                                                    _________
   17. You slam on the brakes when going 75 mph and anyone
       without a seat belt on goes toward the windshield.               _________
   18. You step out of a canoe and the canoe goes backward.             _________

				
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