Question

What is the mass of a baseball that has a kinetic energy of 100 J and is traveling at 5 m/s?

Answer 1

mass = 8 kg.

Explanation:

Given : kinetic energy of 100 J and is traveling at 5 m/s?

To find : What is the mass of a baseball.

Solution : We have given

Kinetic energy = 100 J.

Velocity = 5 m/s.

Kinetic energy =
`(1)/(2)m v^(2)`.

Where m = mass , v = velocity.

Plugging the values

100 =
`(1)/(2)m (5)^(2)`.

100 =
`(1)/(2)m 25`.

On multipkying both sides by 2

200 = 25 m

On dividing both sides by 25

mass = 8 kg.

Therefore, mass = 8 kg.

Answer 2

The formula of the kinetic energy is:
K.E =
`(1)/(2)`mv²

The given are
K.E = 100 J
v = 5 m/s

Plug them in:

100 =
`(1)/(2)`m × (5)²
100 =
`(1)/(2)`m × 25
100 = 12.5m
Divide by 12.5 on either sides to isolate m


`(100)/(12.5)` =
`(12.5m)/(12.5)`
12.5 and 12.5 cancels out
8 kg = m
The mass of the baseball that has a kinetic energy of 100 J and speed of 5 m/s is 8 kg