Exploring Gravity in Space

Why do astronauts feel weightless in space?

• Because there is no gravity in space.

• Because they are in a continuous state of free fall around the Earth.

• Because the space station cancels out gravity.

• Because gravity only acts on objects on Earth.

What force keeps the Moon in orbit around the Earth?

• Magnetic force

• Centrifugal force

• Gravity

• Electric force

What would happen to an object if it stops moving while in orbit around Earth?

• It would float stationary in space.

• It would continue in a straight line due to inertia.

• It would fall towards Earth due to gravity.

• It would move away from Earth into deeper space.

Which of the following best describes orbital mechanics?

• The study of how objects move in space under the influence of their own propulsion.

• The study of how objects move in space under the influence of gravity.

• The study of how planets rotate on their axes.

• The study of how gravity works on Earth.

Why does the International Space Station (ISS) stay in orbit around the Earth?

• Because it is moving at a speed that balances the gravitational pull of the Earth.

• Because it is beyond Earth's gravitational field.

• Because it uses engines to stay in orbit.

• Because it is tethered to Earth.

What is the term for the speed an object needs to stay in orbit around a planet?

• Escape velocity

• Terminal velocity

• Orbital velocity

• Maximum velocity

How does the mass of a planet affect its gravitational pull?

• The greater the mass, the weaker the gravitational pull.

• The greater the mass, the stronger the gravitational pull.

• Mass does not affect gravitational pull.

• Only the mass of the object being pulled affects the gravitational pull.

What is the effect of altitude on the strength of Earth's gravity?

• Gravity increases with altitude.

• Gravity decreases with altitude.

• Gravity is not affected by altitude.

• Gravity reverses with altitude.

What happens to an object's velocity as it moves closer to a planet in orbit?

• It decreases.

• It increases.

• It remains constant.

• It first increases, then decreases.