Gravity Unit Test

Question

Gravity Unit Test
8th Grade
Connections Academy
Please only use this to check your answers.

1. On which object will Earth’s gravity act with the greatest magnitude?

A. a toaster
B. a television
C. a piano***
D. a banana

2. Why does a beach ball weigh less than a bowling ball?

A. The beach ball pushes harder against Earth.
B. The beach ball has more air.
C. The beach ball has more mass.
D. The beach ball is less strongly attracted to Earth.***

3. Which statement about gravitational attraction is correct?

A. All objects on Earth experience the same gravitational attraction.
B. All objects with mass experience gravitational attraction.***
C. Objects with greater volume have a greater gravitational attraction.
D. Objects in space will not have any gravitational attraction.

A spacecraft flies within 500,000 km of each of these planets. Based on its mass, which planet would gravitationally attract the spacecraft the least?

A. Venus
B. Jupiter
C. Neptune
D. Mars***

5. A student conducts an investigation to study the effect of gravity on objects of different masses. Which step should be first in the investigation?

A. Time how long it takes for the objects to fall.
B. Find objects of different masses and measure them.***
C. Drop the objects from a height.
D. Measure the distance between the objects.

6. A science class is conducting an investigation to see how gravity affects objects of different masses. They drop three balls from the same height. They time how long it takes the balls to hit the ground. What are the students comparing?

A. the gravitational attraction of each ball
B. the mass of each ball
C. the height from which each ball is dropped
D. the time it takes for each ball to fall***

7. A hammer and a feather are dropped from the same height. Imagine that there is no resistance to the object's motion in the air. Which value will be different for the two objects?

A. the gravitational attraction between the Earth and the objects***
B. the time it takes for them to fall
C. the velocity of the objects
D. the upward push of air resistance

8. A coin (5 grams), a small parachute (21 grams), and a hammer
(710 grams) are all dropped from a height of 10 meters. The coin and the hammer take about the same amount of time to fall. Which statement describes the time it takes for the parachute to fall?

A. It takes the same amount of time to fall because the effect of gravity is the same.
B. It takes less time to fall because it has the least mass.
C. It takes longer to fall because it experiences greater air resistance.***
D. It takes less time to fall because it has the most surface area.

9. Which object would have the slowest speed at terminal velocity?

A. a 50-kilogram block with no parachute
B. a 10-kilogram block with a small parachute
C. a 10-kilogram block with no parachute
D. a 50-kilogram block with a large parachute***

10. How does an open parachute slow a skydiver’s fall?

A. The parachute changes the mass of the skydiver.
B. The parachute weakens the force of gravity.
C. The parachute pulls the skydiver up.
D. The parachute increases the force opposing gravity.***

11. A science class is planning an investigation about gravity and objects on Earth. In three to four sentences, explain the steps the class should take to provide data to help them make a conclusion about the effect of gravity on objects of different masses. (4 points)

*Your own answer*

12. Two skydivers of different masses jump from a plane. In three to five sentences, explain how their falls compare, including the effects of gravity, mass, and air resistance. (4 points)

*Your own answer*

Bot · Answer

Note: Answers may vary for questions 11 and 12 as they require written responses. The given answers are example responses.

11. To provide data for their investigation, the science class should first find objects of different masses and measure them. Then, they should drop the objects from a height and time how long it takes for them to fall. After gathering data, they can compare the times it took for the different objects to fall and make a conclusion about the effect of gravity on objects of different masses.

12. The skydiver with the greater mass will experience a greater gravitational force and will fall faster than the skydiver with the lesser mass. However, both skydivers will eventually reach terminal velocity, where the force of air resistance will balance the force of gravity and they will fall at a constant speed. The skydiver with the higher mass will require more air resistance to balance the force of gravity, so they may require a larger parachute or more surface area to slow their fall compared to the lighter skydiver.