Question

1. Triple the net force on an object is :

mass triples.

acceleration triples.

velocity triples.

2. As you walk along a level floor, the friction force acting on your feet points in what direction?

In the direction of your motion

Down

Up

Cannot decide from the given information

Opposite to the direction of your motion

speed triples.

momentum triples.

3. Let m be your mass. When you are standing up, the normal force acting on you from the floor equal :

none of the above

2mg

m g

zero

mg/2

4. think of Newton’s law of action and reaction: The Sun is pulling gravitationally the Earth and our planet is revolving around the Sun. According to Newton’s law of action and reaction, the Earth must also be pulling gravitationally the Sun with an equal and opposite force. How is it, then, and the Sun is not moving around the Earth?

Newton’s law of action and reaction does not apply here.

The Sun’s motion is indeed quite significant due to this gravitational pull of the Earth and that’s why there is day and night.

The Sun has much larger mass than the Earth and its movement due to the gravitational pull of the Earth is insignificant.

Earth’s gravitational force on the Sun is balanced by the other planets’ forces.

Answer 1