Question

Nora tied a string around a tennis ball, and then she swung it in a circle in front of her to demonstrate a planet orbiting the Sun. She explained that her hand represented the Sun, the ball represented a planet, and the string kept the ball from leaving the "orbit" around her hand.

Why doesn't the string work in the same way as gravity?

(1 point)
Responses

The string only pulls one way; gravity pulls both ways.
The string only pulls one way; gravity pulls both ways.

The string holding the ball in orbit is a contact force; gravity is a noncontact force.
The string holding the ball in orbit is a contact force; gravity is a noncontact force.

The string keeps the distance between the bodies the same; gravity makes the distance vary.
The string keeps the distance between the bodies the same; gravity makes the distance vary.

There is no difference between the two systems

Answer 1

[AI-generated answer — Bot GPT 3.5]

The string only pulls one way; gravity pulls both ways.

Answer 2

Astronauts on the Moon can jump higher than if they were on Earth. This is because

(1 point)
Responses

there is no friction on the Moon
there is no friction on the Moon

Newton's laws of motion do not apply to the Moon.
Newton's laws of motion do not apply to the Moon.

the astronauts are less massive on the Moon.
the astronauts are less massive on the Moon.

the Moon is less massive than the Earth.

Answer 3

[AI-generated answer — Bot GPT 3.5]

the astronauts are less massive on the Moon.