Question

A ball is dropped 5 meters from rest. Using conservation of energy, what is the final velocity of the ball? a.) 5.39 m/s b.) 4.45 m/s c.) 9.90 m/s d.) 1.23 m/s e.) None of the above

Answer 1

The final velocity of the ball, v = 9.9 m/s

Step-by-step explanation:

It is given that,

A ball is dropped 5 meters from rest, h = 5 meters

We need to find the final velocity of the ball. It can be calculated using the conservation of energy as :

`KE_i+KE_f=PE_i+PE_f`

Initial kinetic energy,
`KE_i=0\ (rest)`

Final kinetic energy,
`KE_f=(1)/(2)mv^2`

Initial potential energy,
`PE_i=mgh`

Final potential energy,
`PE_f=0` (at ground, h = 0)

`(1)/(2)mv^2=mgh`

`v=√(2gh)`

`v=√(2* 9.8\ m/s^2* 5\ m)`

v = 9.89 m/s

or

v = 9.9 m/s

So, the final velocity of the ball is 9.9 m/s. Hence, this is the required solution.