A ball's mass is 1.50 kilograms, and it leaves the racket with a horizontal speed of, say, 90 mph. Find the average force on the tennis ball as it is served.

Question

girlstudy · Answer

@tshimp0629

tshimp0629 · Answer

ohhhhhhhhh eh hahaha ummmmmm 1 sec

tshimp0629 · Answer

ya no i dont remember this stuff

girlstudy · Answer

kk thanks tho

blee1000 · Answer

Im only in 6th grade and I think the average force is 60

girlstudy · Answer

@Ms-Brains

blee1000 · Answer

im sorry

irishboy123 · Answer

you need more info

bum question :-(

girlstudy · Answer

@IrishBoy123 Thats all the info that was given. Is it impossible to do this question?

irishboy123 · Answer

yes

girlstudy · Answer

@IrishBoy123  :(

irishboy123 · Answer

$F = ma = m \dfrac{\Delta v}{\Delta t}$

$F_{average} \cdot \Delta t= m \Delta v$

you have the $m$ and you can assume that $\Delta v = 90mph$

if you knew $\Delta t$, you could also guess $F_{average}$

girlstudy · Answer

@IrishBoy123 Can you substitute T for 9.81?

girlstudy · Answer

@IrishBoy123 Would it make sense to just multiply mass and acceleration only?

irishboy123 · Answer

here, all you can do is calculate the final momentum of the ball. 

you have no idea how that changed with respect to time.  

and Newton's 2nd Law is that Force = rate of change of momentum wrt time.

girlstudy · Answer

@IrishBoy123 Alright, I appreciate the help

irishboy123 · Answer

me too