Gravity assists

In a spaceship gravity assist sligshot around a planet, the magnitude of the spaceship's velocity changes, relative to

• the planet

• the sun

The acceleration of the spacecraft is in the direction of

• the sun

• the planet's orbital motion

• the direction the spacecraft is travelling

To increase the magnitude of its velocity, the spacecraft goes

• in front of the planet as it orbits

• behind the planet as it orbits

To decrease the magnitude of its velocity, the spacecraft goes

• in front of the planet as it orbits

• behind the planet as it orbits

The interaction between spacecraft and planet affects the planet's velocity . . .

• not at all

• negligibly

Gravity assists are used . . .

• to get human passengers to their destination quickly

• to accelerate a spacecraft, when it can't carry enough fuel to do the job

In a slingshot maneouvre, the acceleration on the spacecraft due to gravity and planetary motion is . . .

• in the same direction on the approach and the retreat

• in opposite directions on the approach and the retreat

In a slingshot maneouvre, the acceleration on the spacecraft due to gravity alone is . . .

• in the same direction on the approach and the retreat

• in opposite directions on the approach and the retreat

Use a calculator: If a spacecraft passes by a planet

• ,

• ,

The magnitude of each of these three vectors is . . .

• unknown