Question

1)The highest ocean tides occur when Earth and the Moon are

Lined up with the Sun

At right angles to the Sun

At any angle to the Sun

Lined up during spring

2)A satellite in Earth orbit is above Earth’s

Atmosphere

Gravitational field

Both

Neither

3)What happens to the force of gravity between two objects when their masses are EACH doubled and the distance between them is also doubled.

The force doubles

The force is reduced to ½

The force is increased to 4 x as great

The force remains the same

4)The Sun and the Moon both affect our ocean tides, but the effect of the Moon is greater. Is this because the much smaller moon is closer so it has a stronger gravitational force?

Yes, because the closer distance of the Moon has a greater effect than the mass of the moon when calculating gravitational force.

No, the Sun’s gravitational force is actually much stronger but it is the difference in the pull from one side of the ocean to the other that matters more.

No, because the force of the Moon and Sun on the Earth is the same.

Yes, because the Moon is much denser than the Sun because the Moon is a solid while the Sun is made of gases. This gives the smaller Moon more mass.

5)Why does a person in free fall experience weightlessness, while a person falling at terminal velocity does not?

Weight is felt when there is a support force working against the pull of gravity. In free fall there is no support force.

A person in free fall is weightless because no gravitational force acts upon them, while a person at terminal velocity has gravity pull balanced by air resistance.

The statement is false. A person falling at terminal velocity is also weightless.

A person who is weightless is so far above the surface of the Earth that gravity has no effect on them, but a person in terminal velocity is falling closer and closer to Earth so gravity has an effect.

Answer 1

1) Lined up during spring
2) Atmosphere
3) F = (kMm)/r^2

on doubling the mass and distance, F' = (k*2M*2m)/(2r)^2 =(kMm)/r^2 = F

hence The force remains the same

4) Yes, because the closer distance of the Moon has a greater effect than the mass of the moon when calculating gravitational force.

5)   Weight is felt when there is a support force working against the pull of gravity. In free fall there is no support force.

when only gravity acts on a person and there is no support force, then the person feels weightlessness, hence the person in free fall is weightless.

BUt in case of the person falling at terminal velocity ,in addition to gravity, the falling person is "supported" by air drag.