Question

What’s the force of a pitching machine on a baseball? Baseballs pitched by a machine have a horizontal velocity of 30 meters/second. The machine accelerates the baseball from 0 meters/second to 30 meters/second in 0.5 seconds. If a baseball has a mass of 0.15 kilograms, the force the machine exerts is newtons. Use F = ma, where  .

Answer 1

So F=ma

The acceleration of the baseball is:

where and are the final and initial speed of the ball, and is the time interval in which the force acted.

Replacing the numbers, we get

And at this point, we can use Newton's second law F=ma to find the value of the force of the pitching machine:

Answer 2

The acceleration of the baseball is:

`a= (v_f-v_i)/(\Delta t)`
where
`v_f` and
`v_i` are the final and initial speed of the ball, and
`\Delta t` is the time interval in which the force acted.

Replacing the numbers, we get

`a= (30 m/s-0m/s)/(0.5 s)=60 m/s^2`
And at this point, we can use Newton's second law F=ma to find the value of the force of the pitching machine:

`F=ma=(0.15 kg)(60 m/s^2)=9 N`