Question

Use the table of criteria for an investigation to answer the question.

Effect of Object Mass and Drop Height on Gravitational Study
Object To Be Dropped Drop Height (meters)
10-gram ball 5
5-gram ball 8
18-gram ball 10
A student designs an investigation to study the effect of gravity on objects on Earth. He will use the criteria shown. How can the student improve the investigation?

(1 point)

by dropping the balls from the same height

by measuring the circumference of the balls

by using balls that are the same mass

by finding balls made from different materials

Answer 1

by dropping the balls from the same height

Explanation: To test the effect of mass you must keep drop height constant so height is not a confounding variable (or conversely, to test drop height you must keep mass constant).