Gravity — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. Why does the Moon stay in orbit around the Earth instead of flying off into space?
A) Earth's gravity keeps pulling the Moon toward Earth as it moves
B) The Moon is attached to Earth by an invisible rope
C) The Sun blocks the Moon and stops it from leaving
D) The Moon has no mass, so nothing can pull it away
Grade 5 science teaches that Earth's gravity continually pulls the Moon, curving its path into an orbit.
2. What keeps the Earth itself in orbit around the Sun?
A) Earth pushes against the Sun and bounces around it
B) The Sun's gravity pulls the Earth as the Earth moves forward
C) The Moon pushes the Earth around the Sun
D) Air in space slowly carries the Earth in a circle
Grade 5 students explain that the Sun's strong gravity pulls Earth into a curved orbit.
3. What is the main cause of the rise and fall of ocean tides on Earth?
A) Wind blowing very hard across the surface of the oceans
B) Earth shaking and pushing the water up and down each day
C) The pull of gravity from the Moon and the Sun on the oceans
D) Hot water rising and cold water sinking in the deep sea
Grade 5 science teaches that the Moon's and Sun's gravity pull ocean water, creating tides.
4. Which statement best describes gravity throughout the solar system?
A) Gravity only exists on the planet Earth and nowhere else
B) Every object that has mass pulls on every other object with mass
C) Only stars like the Sun have gravity; planets and moons have none
D) Gravity disappears in outer space because there is no air
Grade 5 students learn that all objects with mass attract one another through gravity.
Part B: Fill in the Blank
Write the correct answer on each line.
1. The curved path that the Moon follows as it travels around the Earth is called an orbit.
Grade 5 science names a curved path around another body an orbit.
2. The daily rise and fall of ocean water along beaches is called the tide.
Grade 5 students label the rise and fall of ocean water as the tide.
3. Tides are caused mostly by the gravity of the Moon pulling on Earth's oceans.
Grade 5 science teaches that the Moon's gravity is the main cause of tides.
4. Earth and the other planets travel around the Sun because of its strong gravity.
Grade 5 students explain that the Sun's gravity pulls planets into orbit around it.
5. Any two objects that have mass pull on each other through gravity, even in space.
Grade 5 learners know that all masses attract one another through gravity.