Space Science Exam 2 - Review Questions

Which of the following is not changing for someone driving a car in a circle at 30 miles per hour?

speed

What does a force acting on an object do to that object's motion?

A force changes an object's momentum

You are weightless if

a or c (no force acts on you) & (you are freely falling in gravity)

Newton's second law of motion states that

the acceleration of an object is equal to the force acting on it divided by its mass

Which of the following describes how a rocket takes off?

The rocket exerts a force on the exhaust, thus the exhaust exerts a force on the rocket, accelerating it

When a ball is dropped, some of the ball's energy changes from

gravitational potential energy to kinetic energy

How does the force of gravity between two objects depend on the distance between the objects?

It increases in proportion to 1/distance squared

The total mass of a gravitationally bound two-body system can be determined from

Newton's version of Kepler's third law

Tidal forces from the Moon and Sun add up to make larger tides on Earth when the Moon is

a and b (new) & (full)

We can't see infrared light, but we can perceive it as

Heat

Which is likely to originate from the hottest—most energetic—object?

Gamma rays

When an electron in an atom jumps from a high-energy orbital to a lower-energy one, what happens?

A photon of light is emitted

Since each element has a different number of protons and electrons and a different pattern of orbitals,

All of the above

If a source of light is moving away from you, all the wavelengths are:

Shifted to longer wavelengths (Doppler shifted)

The largest optical telescopes are designed to have

Large collecting area and high angular resolution—the magnification is of secondary importance

Which planets have a rocky, relatively dense composition?

Mercury, Venus, Earth, and Mars

Why do we think that the solar system formed from a rotating, collapsing gas cloud that ended up as a disk orbiting the Sun?

All of the above

What do we think the composition of the solar nebula was?

About 98% hydrogen and helium, and 2% heavier elements

What do we think condensed out of the solar nebula?

All except a (a is hydrogen and helium)

Why could the Jovian planets grow to be much larger than the terrestrial planets?

They formed beyond the frost line where ices can condense so they included hydrogen compounds

Where do asteroids come from?

Leftover planetesimals from the inner solar system

Where do comets come from?

Leftover planetesimals from the outer solar system

The dense, rocky, and metallic planets are found close to the Sun because

Rocks and metals condensed at the relatively high temperatures close to the Sun

Where did Earth's (interior) heat come from?

All of the above

How does the cooling of planets and potatoes vary with size?

All of the above

What is the source of Earth's magnetic field?

Molten metal circulating inside of Earth, moving electrons like in a wire

If Earth didn't have an atmosphere, what would happen to its temperature?

It would go down a lot

Why are smaller terrestrial bodies such as Mercury or the Moon “geologically dead”?

They cooled off faster than Earth did

Why is the sky blue?

The blue light in white sunlight scatters more than red light