Newton’s Three Laws of Motion

1. Who was Isaac Newton? Write a brief paragraph mentioning when/where he was born and educated, what scientific achievements he is known for, and other noteworthy personalities alive and working during his life.

Newton’s First Law

http://www.glenbrook.k12.il.us/gbssci/phys/Class/newtlaws/u2l1a.html

2. Explain the first law showing that you understand the term inertia.

3. There are many applications of Newton's first law of motion. Several applications are listed below. Pick any two of these and explain how the first law applies – what body’s state of motion is being changed. Additionally, write two other possible common applications

* Blood rushes from your head to your feet while quickly stopping when riding on a descending elevator.

* The head of a hammer can be tightened onto the wooden handle by banging the bottom of the handle against a hard surface.

* A brick is painlessly broken over the head of your science teacher by slamming it with a hammer.

* To dislodge ketchup from the bottom of a ketchup bottle, it is often turned upside down and thrusted downward at high speeds and then abruptly halted.

* Headrests are placed in cars to prevent whiplash injuries during rear-end collisions.

* While riding a skateboard, you fly forward off the board when hitting a curb or rock or other object which abruptly halts the motion of the skateboard.

Newton’s Second Law

http://www.glenbrook.k12.il.us/gbssci/phys/Class/newtlaws/u2l3a.html

F_net = m * a

4. Explain this formula as it applies to Newton’s second law.

5. Using this equation fill in the missing cells.

Net Force (Newtons)	Mass (kg)	Acceleration (m/sec./sec)
10	2
20	2
	2	5
10		10

Newton’s Third Law

http://www.glenbrook.k12.il.us/gbssci/phys/Class/newtlaws/u2l4a.html

“For every action, there is an equal and opposite reaction.”

6. Explain the above statement as it applies to Newton’s third law

7. While driving down the road, a fly strikes the windshield of a bus and makes a splatty mess. This is a clear case of Newton's third law of motion. The fly hits the bus and the bus hits the fly. Which of the two forces is greater: the force on the firefly or the force on the bus? Explain.

8. Many people are familiar with the fact that a rifle recoils when fired. This recoil is the result of action-reaction force pairs. A gunpowder explosion creates hot gases which expand outward allowing the rifle to push forward on the bullet. Consistent with Newton's third law of motion, the bullet pushes backwards upon the rifle. The acceleration of the recoiling rifle is ...

a. greater than the acceleration of the bullet.

b. smaller than the acceleration of the bullet.

c. the same size as the acceleration of the bullet.

9. For years, space travel was believed to be impossible because there was nothing which rockets could push off of in space in order to provide the propulsion necessary to accelerate. This inability of a rocket to provide propulsion is because ...

a. ... space is void of air so the rockets have nothing to push off of.

b. ... gravity is absent in space.

c. ... space is void of air and so there is no air resistance in space.

d. ... nonsense! Rockets do accelerate in space and have been able to do so for a long time.

10. In the top picture a man is pulling upon a rope which is attached to a wall. In the bottom picture, the man is pulling upon a rope which is attached to an elephant. In each case, the force scale reads 500 Newtons. The man is pulling ...

a. with more force when the rope is attached to the wall.

b. with more force when the rope is attached to the elephant.

c. the same force in each case.