Question

Which of the following statements are correct? (Select all that apply.)

It is possible to have forces on an object in the absence of motion of the object.It is possible for an object to have motion in the absence of forces on the object.None of these answers are correct.

A passenger sitting in the rear of a bus claims that he was injured when the driver slammed on the brakes after a dog jumped out in front of the bus, causing a suitcase to come flying toward the passenger from the front of the bus. If you were the judge in this case, would you believe him?

NoYes    
In Case A an object is moving straight downward with a constant speed of 9.80 m/s, while in Case B an object is moving straight downward with a constant acceleration of magnitude 9.80 m/s². Which one of the following is true?

a nonzero net external force acts on the object in Case A only. a nonzero net external force acts on the object in both cases.     a nonzero net external force acts on the object in neither case.a nonzero net external force acts on the object in Case B only.

Answer 1

1)correct- It is possible to have forces on an object in the absence of motion of the object.It is possible for an object to have motion in the absence of forces on the object.

2)correct-no i dont believe him because after brakes it should not move to the back but towards the front

3)a nonzero net external force acts on the object in Case B only, this is correct becauseit has acceleration