Question

A man is standing on the edge of a 20.0 m high cliff. He throws a rock horizontally with an initial velocity of 10.0 m/s.

a. How long does it take to reach the ground?
b. How far does the rock land from the base of the cliff?

Answer 1

a. The rock takes 2.02 seconds to hit the ground

b. The rock lands at 20,2 m from the base of the cliff

Step-by-step explanation:

Horizontal motion occurs when an object is thrown horizontally with an initial speed v from a height h above the ground. When it happens, the object moves through a curved path determined by gravity until it hits the ground.

The time taken by the object to hit the ground is calculated by:

`\displaystyle t=\sqrt{(2h)/(g)}`

The range is defined as the maximum horizontal distance traveled by the object and it can be calculated as follows:

`\displaystyle d=v.t`

The man is standing on the edge of the h=20 m cliff and throws a rock with a horizontal speed of v=10 m/s.

a,

The time taken by the rock to reach the ground is:

`\displaystyle t=\sqrt{(2*20)/(9.8)}`

`\displaystyle t=√(4.0816)`

t = 2.02 s

The rock takes 2.02 seconds to hit the ground

b.

The range is calculated now:

`\displaystyle d=10\cdot 2.02`

d = 20.2 m

The rock lands at 20,2 m from the base of the cliff