An object is dropped from rest near the surface of Earth.If the time interval during which it falls is doubled,the distance it falls will
A)double.
B)decrease by one-half.
C)increase by a factor of four.
D)decrease by a factor of four.
E)not change.

Question

Quizplus · Accepted Answer

The distance an object falls is given by the equation:
d = 1/2gt^2 ,
where d is the distance, g is the acceleration due to gravity (9.8 m/s^2 near the surface of the Earth), and t is the time.
If the time interval is doubled, then the new time is 2t. Plugging this into the distance equation, we get:
d = 1/2g(2t)^2 = 1/2g(4t^2) = 2g(t^2) = 2d,
which shows that the distance the object falls will increase by a factor of four. So, the best choice is C.

An Object Is Dropped from Rest near the Surface of Earth.If