Question

1.

Suppose an ice skater is moving on the surface of a frozen lake at constant velocity. What is true about the external (outside) forces acting on the skater?

There are none.

There could be some but they all cancel out.

Gravity can be ignored.

The all are perfectly horizontal.

2.

Your class is rather unhappy with the instructor, and they pitch in and decide to fund a sabbatical for him to go to Mars. Unbeknownst to the students the following semester, the instructor has made long distance course arrangements so the “show can go on”. The instructor begins talking about mass, weight and related things. He correctly makes which following statement:

his mass is still essentially unchanged but his weight is less than on earth.

his weight is still essentially unchanged but his mass is less than on earth.

neither his weight nor his mass have changed much.

his weight and mass have both changed significantly.

3.

A motion defined in two planes is

1D motion

2D motion

3D motion

None of the above

4.

What causes a gyroscope to continue spinning?

		Inertia
		Gravity
		Acceleration
		Internal force

Answer 1

1) option B is correct

There is gravitational force , normal force, air resistance, et .but they cancel out..

2)option a is correct

Mass of a person is constant throughout but since weight is a force exerted by planet, hence weight changes as a person leaves a planet (or any gravitational field )

3) option B is correct

4) options a is correct,