SCI Week 5 Day 3

A student reads a list of several measurements:

1. The amount of dust given off by exploding stars

2. The rate at which galaxies are moving away from Earth

3. The rate at which the light emitted by a star switches between red and blue wavelengths

4. The amount of hydrogen present in stars

Which measurements are used as evidence of the age of the universe?

• 1 and 2

• 2 and 3

• 1, 2, and 3

• 1, 2, and 4

Stars in the universe vary in size, luminosity, and temperature. The Hertzsprung-Russell diagram helps astronomers categorize the stars.

Which type of starts the dimmest?

• Blue giants

• Red giants

• Red supergiants

• White dwarfs

What is the main cause of tides on Earth?

• Earth’s rotation on its axis causing surface water to move

• Moon’s gravitational pull on the Earth

• Earth’s strong winds blowing water onto coasts

• Earth’s revolution around the Sun

As the distance between the Earth and a satellite increases, what will happen to the gravitational attraction between them?

• It will increase.

• It will decrease.

• It will remain the same.

• It will initially increase then decrease.

What tool helps scientists determine the chemical composition of distant stars?

• Microscope

• Optical telescope

• Space probe

• Spectroscope