Calculating Force of Bat on Ball: Physics Homework Solution

[futureteacher]

Homework Statement

A 0.145 ball is pitched at 37 m/s and is hit on a horizontal line drive at 51.5 m/s. If the contact time between the ball and the bat is 3.5x10^-3 seconds what is the avg force between the bat and the ball during contact.

Homework Equations

P=mv
$$\Sigma$$F=$$\Delta$$P/$$\Delta$$T

m_final*v_final-m_initial*v_initial/$$\Delta$$Time

factor out m (mass)
m(vfinal-vinitial)/$$\Delta$$t

The Attempt at a Solution

0.145kg(51.5m/s-37.0m/s)/(3.5*10^-3)

i get 600N but my webwork says that not right i have no idea what I am doing wrong

 

[Andrew Mason]

Homework Statement

A 0.145 ball is pitched at 37 m/s and is hit on a horizontal line drive at 51.5 m/s. If the contact time between the ball and the bat is 3.5x10^-3 seconds what is the avg force between the bat and the ball during contact.

Homework Equations

P=mv
$$\Sigma$$F=$$\Delta$$P/$$\Delta$$T

m_final*v_final-m_initial*v_initial/$$\Delta$$Time

factor out m (mass)
m(vfinal-vinitial)/$$\Delta$$t

The Attempt at a Solution

0.145kg(51.5m/s-37.0m/s)/(3.5*10^-3)

i get 600N but my webwork says that not right i have no idea what I am doing wrong

The change in velocity is 51.5 + 37.0 m/s. The ball is hit in the opposite direction to the pitch.

Don't forget that force and momentum are vector quantities. The definition of force is:

$$\vec F = \sum \vec F_i = \frac{d\vec p}{dt}$$

AM

 

[tomcue]

I would first check to make sure that all of the units are consistent. In this case, it looks like there may be an issue with the units of time. The contact time is given in seconds, but the units in the equation are in milliseconds. This could be causing the discrepancy in the answer.

Additionally, it is important to consider any external forces acting on the ball or bat, such as air resistance or gravity. These forces may affect the final answer.

Another factor to consider is the elasticity of the collision between the bat and ball. If the collision is not perfectly elastic, some of the energy may be lost, resulting in a lower force between the bat and ball.

Without knowing the specific details of the problem and the given answer, it is difficult to determine exactly where the error may be. However, it is important to carefully check all units and assumptions when solving physics problems to ensure accurate results.