Determining the time of a collision

[robertmatthew]

Homework Statement

A 473-gram baseball traveling at 37 m/s is hit directly back at the pitcher with a speed of 45 m/s. If the force of contact between the bat and the ball is 3800 Newtons, how long is the bat in contact with the ball?

Homework Equations

F= dp/dt

The Attempt at a Solution

F=dp/dt
t=dp/F
t=(m)(v₂-v¹)/F
t=(.473)(8)/(3800) ---> converted 473g into kg because Newtons are kg*m/s²
t=.000996 s

But that's not the right answer. I've also tried not converted g->kg and that doesn't work either, so obviously there's something else I'm doing wrong, but I just don't know what it is.

 

[Dick]

Homework Statement

A 473-gram baseball traveling at 37 m/s is hit directly back at the pitcher with a speed of 45 m/s. If the force of contact between the bat and the ball is 3800 Newtons, how long is the bat in contact with the ball?

Homework Equations

F= dp/dt

The Attempt at a Solution

F=dp/dt
t=dp/F
t=(m)(v₂-v¹)/F
t=(.473)(8)/(3800) ---> converted 473g into kg because Newtons are kg*m/s²
t=.000996 s

But that's not the right answer. I've also tried not converted g->kg and that doesn't work either, so obviously there's something else I'm doing wrong, but I just don't know what it is.

The difference in velocities between 37m/s towards the bat and 45m/s away from the bat is 82m/s. You have to consider the sign of the velocities.

 

[robertmatthew]

Wow, that completely went over my head... now I feel really stupid, haha. Thanks for pointing that out, sorry for the waste of a post.

 

[Dick]

Wow, that completely went over my head... now I feel really stupid, haha. Thanks for pointing that out, sorry for the waste of a post.

Don't feel sorry. That's what the forum is for. If you get it the post is hardly wasted.

 

[Nickie]

I would like to point out that there are a few assumptions and limitations to consider when trying to determine the time of a collision between a baseball and a bat. Firstly, the calculations provided in the attempt at a solution assume that the collision between the baseball and the bat is perfectly elastic, meaning there is no loss of energy during the collision. However, in reality, there will be some energy lost due to factors such as air resistance and friction between the ball and the bat. This can affect the accuracy of the calculated time of the collision.

Additionally, the calculations also assume that the force of contact between the bat and the ball is constant throughout the entire duration of the collision. In reality, the force may vary depending on the materials and structure of the bat and ball, and the angle at which the bat makes contact with the ball.

Furthermore, it is important to note that this calculation only provides an estimate of the time of the collision and may not accurately reflect the actual duration of the contact between the bat and the ball. Other factors such as the speed and trajectory of the bat swing, as well as the shape and size of the ball, can also affect the duration of the collision.

In conclusion, while the provided attempt at a solution may provide a rough estimate of the time of the collision, it is important to consider the assumptions and limitations involved in the calculation and to acknowledge that the actual duration of the collision may vary from the calculated value. Further experimentation and analysis may be necessary to accurately determine the time of a collision between a baseball and a bat.