Physics 11, kinetic energy problem

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Homework Help Overview

The discussion revolves around a kinetic energy problem related to a tennis player's racquet exerting force on a ball. The problem involves calculating the kinetic energy of the ball given its mass, the force applied, and the time of contact with the racquet.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the need to find both mass and velocity to calculate kinetic energy. There are mentions of using impulse and equations related to momentum and velocity. Some participants express uncertainty about how to proceed without knowing the distance.

Discussion Status

Some participants have provided hints and guidance regarding the use of impulse and the relationship between momentum and velocity. There is an ongoing exploration of the problem, with some participants attempting calculations and sharing their results.

Contextual Notes

Participants note the absence of distance information, which is a point of concern in their calculations. The original poster expresses uncertainty about the starting point for solving the problem.

Iceclover
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Hey if anyone could help me work through a couple of problems that would be great!:smile:

Homework Statement



It is not uncommon during the service of a professional tennis player for the racquet to exert an everage force of 150.0N on the ball. If the ball has a mass of 0.060kg and is in contact with the strings of the racquet for 0.030s what is the kinetic energy of the ball as it leaves the racquet? Assume the ball starts from rest


Homework Equations



Ek=1/2mv^2

The Attempt at a Solution


I'm not sure really where to start here...
 
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A hint: impulse.
 
Well, you know what you'll need to find Kinetic Energy--mass and velocity. You're given mass. Can you think of any other equations that might help you find velocity?
 
what do i do once I've figured that out?
 
d=vt but i don't have a distance either
 
Once you've figured what out?
 
oh my god i think i got it, will someone let me know if i got it right, just let me work it out.
 
There is no need to create so many posts. :wink:
 
i got 169J
 
  • #10
Looks OK to me, whose brain is fried!
 
Last edited:
  • #11
Iceclover said:
i got 169J

That's correct.
 
  • #12
p=Ft
p=150(0.030)
p=4.5

p=mv
4.5=(0.06)(v)
v=75m/s

Ek=1/2m^2
Ek=1/2(0.060)(75^2)
Ek=169J
 
  • #13
Ok i have a couple of other question so if anyone wants to stick around and help...?
 

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