Measuring Gravity at the Surface of the Earth

time t in seconds

0

vertical distance d in meters

20

t = 0 seconds

d = 20 meters

The object has not hit the ground.

How can you measure the acceleration due to gravity at the Earth's surface? Drop an object from a known height and measure the time it takes to hit the ground. Then use the formula for a falling object,

d=

1

2

g

2

t

, to calculate

g=2d/

2

t

.