How Is Impulse Calculated in Tennis Ball Physics?

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Homework Help Overview

The discussion revolves around the calculation of impulse in the context of a tennis ball being hit vertically by a racket. The problem involves determining the impulse imparted to a 58.0g tennis ball that reaches a height of 5.50m after being struck.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to apply the principles of momentum and energy conservation but expresses uncertainty about the connection between the potential energy gained by the ball and the impulse calculated. Some participants suggest calculating the gravitational potential energy to deduce the ball's speed after impact, while others provide momentum equations to relate initial and final states.

Discussion Status

Participants are exploring various aspects of the problem, including the relationship between energy and impulse, and the application of momentum conservation. There is a clear emphasis on understanding the underlying physics rather than providing a complete solution. Guidance has been offered regarding the conservation of energy and momentum, but no consensus has been reached on the final approach.

Contextual Notes

Participants are reminded of the forum's rules against providing complete solutions, which may influence the depth of responses and the direction of the discussion.

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Homework Statement


To warm up for a match, a tennis player hits the 58.0g ball vertically with her racket.
If the ball is stationary just before it is hit and goes 5.50m high, what impulse did she impart to it?

I know that the answer is 0.602 kgm/s but I don't understand why this is the answer

Homework Equations


P=mv

ptotal = Pinitial + Pfinal

The Attempt at a Solution


Pinitial = (0.058kg)(0 m/s)
= 0

Pfinal = (0.058kg)(vfinal

I'm not sure where to go from here.
I think that kinitial+Uinitial = kfinal+ufinal has something to do with it
But I'm not sure.
 
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Energy is conserved. If the ball reaches a height of 5.50 m, it has gained a certain amount of gravitational potential energy (you can calculate the amount). That energy had to come from somewhere. From this fact, you can deduce the speed of the ball at the end of the impact with the racket. ;)
 
compute v(0) tennis ball: v(t)[/2] = v(0)[/2] - 2*g*d → 0 = v(0)[/2] - 2*9.8*5.5 = 10.38 m/s.

ƩP(initial) = ƩP(final) (just before and just after the hit). In general p=mv.

Initial m(b)*v(b) + m(r)*v(r) = 0+ m(r)*v(r)

Final m(b)*v(b) + m(r)*v(r) = 0.058*10.38=0.602 kgm/s

So initial momentum racket is 0,602 kgm/s.
 
Fredb, we do NOT provide complete solutions to homework problems on this site. It is against site rules.
 

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