Force and Newton's Law

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Force and Newton’s Laws

Use the following terms to complete the sentences below.

net force second law third law acceleration rolling velocity

normal force friction inertia force sliding static

velocity 1. When more than one force is acting on an object, the determines the motion of the object.

force 2. When you throw a ball, your hand applies ______ to the ball.

friction 3. is the force that brakes use to stop the car.

Acceleration 4. tells how velocity changes.

Normal force 5.If an object is placed on a flat surface,the is straight up and is equal to the weight of the object.

Third law 6. “Forces always act in equal but opposite pairs” is Newton’s of motion.

First law 7. Every time you change your speed or direction, Newton’s describes it’s force or action.

inertia 8. The tendency of an object to resist a change in motion is called .

Match the terms in Column 2 with the descriptions in Column 1. Write the letter of the correct term in the blank to the left.

__b____9. An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an outside force.

_g_____10.The relationship between an object's mass m, its acceleration a, and the applied force F is a= F/m.

_c____11. A push or a pull

_h_____12. Forces always act in equal but opposite pairs.

a 13. Two forces whose effects cancel each other out.

d 14. The rubbing force that acts against motion between two surfaces.

e 15. The total force acted upon by an object.

Mark each statement with either true or false.

T 16. When the net force is zero, the forces on an object are balanced.

F 17. If two forces act in the same direction, they cancel each other out.

T 18. According to Newton’s first law of motion, an object at rest will remain at rest until a force acts upon it.

T 19. If an object is not moving the net force working on it is zero.

F 20. Walking would be impossible without rolling friction.

T 21. Friction brings most objects to stop.

T 22. According to Newton’s first law, an object moving will continue moving in that direction at a constant speed until a new force acts upon it.

Do the following calculations. Show your work in the space provided

23.What force must be applied to a 10 kg object in order to make it accelerate at 6 m/s²?

F=ma= (10 kg) (6 m/s²)= 60 N

24. If Keith dropped a ball of the school at the acceleration of gravity to the earth and the force applied was 200 N. What was the mass of the ball?

M=f/a= (200 N)/(9.8 m/s²)= 20 kg

25. If Anastacia’s horse weighs 600 kg, what is the force you will have to apply to accelerate 5 m/s²?

F=ma= (600 kg) (5 m/s²)= 3000 N

For each of the following, circle the letter of the term or phrase that best completes the sentence.

26. A(n) __c___ is a push or a pull.