Question

An 3-kg object is dropped from a height of 5 m. The rock has an impact speed

of

Answer 1

The rock has an impact speed of 9.9 m/s.

Step-by-step explanation:

given information:

object's mass, m = 3 kg

height, h = 5 m

in this case, the potential energy is equal to the kinetic energy

PE = KE

mgh =
`(1)/(2)` mv²

where

m = mass (kg)

g = gravitational constant (9.8 m/s²)

v = velocity (m/s)

so,

mgh =
`(1)/(2)` mv²

gh =
`(1)/(2)` v²

v² = 2gh

v = √2gh

= √(2)(9.8)(5)

= 9.9 m/s