# science

posted by
**katie**
.

A rock tumbles straight down from a cliff, its moving at 20 m/s when it hits. What is the height of the cliff? The mass of the rock is 8 kg.

a) 2.5 m

b) 400 m

C) 20.4 m

d) 160 m

posted by
**katie**
.

A rock tumbles straight down from a cliff, its moving at 20 m/s when it hits. What is the height of the cliff? The mass of the rock is 8 kg.

a) 2.5 m

b) 400 m

C) 20.4 m

d) 160 m