A baseball (m = 151 g) approaches a bat horizontally at a speed of 39.8 m/s (89 mi/h) and is hit straight back at a speed of 45.7 m/s (102 mi/h). If the ball is in contact with the bat for a time of 1.05 ms, what is the average force exerted on the ball by the bat? Neglect the weight of the ball, since it is so much less than the force of the bat. Choose the direction of the incoming ball as the positive direction.

Force * contact time = impulse

= momentum change
= 0.151 kg*(45.7 + 39.8)m/s

Solve for the force in Newtons. You do not have to consider the weight of the ball, since it is in a different (vertical) direction from the force of the bat, anyway. The choice of positive direction also doesn't matter. Whoever wrote this question is just making it harder with the "hints".

When I did this I got the answer 12.91 prior to you responding to me and when I tried the way you said I received the same answer but our software is telling me that its wrong and i tried twice.

The work is correct you just need to multiply the answer by 1000.

To find the average force exerted on the ball by the bat, we can use the impulse-momentum principle. The impulse-momentum principle states that the change in momentum of an object is equal to the net external force acting on it multiplied by the time interval over which the force is applied.

The momentum of an object is given by the product of its mass and velocity. In this case, we have the initial velocity of the ball (v1 = 39.8 m/s) and the final velocity of the ball (v2 = -45.7 m/s).

First, let's find the initial momentum of the ball:
p1 = m * v1
p1 = (0.151 kg) * (39.8 m/s)

Next, let's find the final momentum of the ball:
p2 = m * v2
p2 = (0.151 kg) * (-45.7 m/s)

Now, we can find the change in momentum:
Δp = p2 - p1

Since momentum is a vector quantity, positive and negative signs represent the direction of the momentum. In this case, the initial velocity is positive, and the final velocity is negative. Therefore, the change in momentum is calculated as:
Δp = (-45.7 kg·m/s) - (0.151 kg) * (39.8 m/s)

Now, we need to convert the time interval from milliseconds to seconds:
Δt = 1.05 ms = 0.00105 s

Finally, we can calculate the average force using the impulse-momentum principle:
F_avg = Δp / Δt

Substituting the values we have calculated:
F_avg = [(0.151 kg) * (-45.7 m/s) - (0.151 kg) * (39.8 m/s)] / (0.00105 s)

Evaluating this expression will give you the average force exerted on the ball by the bat.