# Bat hits baseball

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1. Oct 24, 2014

### gnome222

<< Moderator Note -- thread moved to the HH forums >>

a pitcher throws a 1.5kg baseball with speed 25m/s. it hits the bat and return in opposite direction with same speed. the force that bat exerted on ball is 50N. For how long was the bat touching(in contact) the ball? I used: delat t * F = m*delta velocity delta t 50N = 1.5(25-(-25)) and i got t=1.5 s. Is it correct? It does not seem like.

Last edited by a moderator: Oct 24, 2014
2. Oct 24, 2014

### Staff: Mentor

That's a pretty happy baseball. Are you sure of that 1.5 kg?

Chet

3. Oct 24, 2014

### gnome222

yes

4. Oct 24, 2014

### Staff: Mentor

A major league baseball has a mass of 5.25 oz (0.15 kg). That 1.5 kg is an obvious typo.

And, please, don't try to play baseball with a 1.5 kg baseball. If you got hit by a fastball, it would be "lights out."

Chet

5. Oct 24, 2014

### gnome222

o
ok, but under the conditions described what would be time?

6. Oct 24, 2014

### Staff: Mentor

If you are asking whether you solved the problem correctly, given the obviously faulty data, then the answer is yes.

Chet

7. Oct 28, 2014

### Sharath K Menon

force is the rate of change of momentum.
Thus, you have been given the change in momentum, the force excerted.
So,
t=Change in momentum/force
=2*1.5*25/50=75/50=1.5