A rock is thrown horizontally off of a cliff with a velocity of 20 m/s. The rock lands 60 m from the base of the cliff. How long will the rock be in the air?

The time spent by the rock in air is 3 s.

Explanation:

Given;

initial  horizontal velocity of the rock, u = 20 m/s

horizontal distance traveled by rock, R = 60 m

The the range of the projectile is given by;

R = vt

where;

v is the initial  horizontal velocity of the rock

t is the time spent by the rock in air

t = R/v

t = 60 / 20

t = 3 s

Therefore, the time spent by the rock in air is 3 s.

real, smaller and upside-down.   so the answer should be b.