5 questions !

1. what is Newton's first law known as? The law of _____?

A- friction

B- Mass

C- gravity

D- inertia

2. 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 that expand outward allowing the rifle to push forward on the bullet. Consistent with Newton's third law of motion, the butlet pushes backwards upon the rifle. The acceteration of the recoiling rifle is...

A- greater than the acceleration of the bullet.

B- smaller than the acceleration of the bullet.

C- two times greater than the acceleration of the bullet.

D- the same size as the acceleration of the bullet.

3. The fact that a large cruise ship can float in water is an example of what ?

A- weight

B- buoyant force

C- volume

D- friction

4. Devices such as seat belts and air bags are used to protect passengers from which one of Newton's laws ?

A- law of action/reaction

B- none of these

C-law of inertia

D-law of acceleration

5. Which of the following affect friction ?(you can choose one or more than 1)

* hight

* weight

* length

* roughness of surface