Calculating Force on a Ball at an Angle

[faiziqb12]

Homework Statement

a mass of 100g strikes the wall with speed 5 m/s at an angle of 60 degrees to the wall and it rebounds with the same speed. if the contact time is 2 * 10^ -3 , what is the force applied by the wall and in what direction?

The Attempt at a Solution

I tried solving the question by using the wall as the y-axis and finding the acceleration along the y component of the velocity..
but I come up with the answer 250 which is wrong
the correct answer is 250 * underoot 3 and the direction is given to the left please explain how

thanks in advance

 

[BvU]

Hello scary one,

You may assume there is no force (so no acceleration) in the y direction: the ball appears to bounce off with the same speed.

In the x-direction, however, drastic things happen: first it moves at some speed towards the wall and after the bounce it has the same speed but in a negative x direction. So there is a big $\Delta v$. Your job is to calculate a from that with the relevant formula (oops )

 

[faiziqb12]

thanks bvu.
I got it right now.