Solar Systm REVIEW Test #2

Which of the following is an example in which you are traveling at constant speed but not at constant velocity?

• driving backward at exactly 50 km/hr

• driving around in a circle at exactly 100 km/hr

• rolling freely down a hill in a cart, traveling in a straight line

• jumping up and down, with a period of exactly 60 hops per minute

• none of the above

Standing on the surface of the Earth you drop a rock down a well and it falls for 5 seconds before hitting the bottom. How fast is it moving when it hits the bottom of the well? Neglect air resistance.

• It depends on how heavy it is.

• It depends on what shape it is.

• 50 m/s

• 10 m/s

• 15 m/s

Momentum is defined as

• mass times velocity.

• force times velocity.

• mass times speed.

• force times acceleration.

• mass times acceleration.

If an object's velocity is doubled, its momentum is

• halved.

• dependent on its acceleration

• unchanged

• doubled

• quadrupled

As long as an object is not gaining or losing mass, a net force on the object will cause a change in

• weight

• speed

• acceleration

• velocity

• direction

If your mass is 60 kg on Earth, what would your mass be on the Moon?

• 10 kg

• 10 lb

• 50 kg

• 60 lb

• 60 kg

In which of the following cases would you feel weightless?

• while traveling through space in an accelerating rocket

• while falling from an airplane with your parachute open

• while falling from a roof

• while walking on the Moon

• none of the above

What would happen if the Space Shuttle were launched with a speed greater than Earth's escape velocity?

• it would orbit Earth at a faster velocity

• It would travel away from Earth into the solar system.

• It would travel in a higher orbit around the Earth

• It would be in an unstable orbit.

• It would take less time to reach its bound orbit

Speed and velocity are the same thing.

• True

• False

The acceleration of gravity on Earth is approximately 10 m/s² (more precisely, 9.8 m/s²). If you drop a rock from a tall building, about how fast will it be falling after 3 seconds?

• 10 m/s

• 10 m/s2

• 30 m/s

• 30 m/s2

• 20 m/s