- #1

Nightrider55

- 18

- 0

## Homework Statement

Fred (mass 60.0kg) is running with the football at a speed of 6.0m/s when he is met head-on by Brutus (mass 120kg), who is moving at 4.0m/s. Brutus grabs Fred in a tight grip, and they fall to the ground. How far do they slide?

Part A

The coefficient of kinetic friction between football uniforms and Astroturf is 0.3.

Give answer in cm

## Homework Equations

MfVf + MbVb=(Mf+Mb)Vs

Kinematics

Ax=-mew x g

## The Attempt at a Solution

I did the problem and doubled check my work and even had a friend check it and we couldn't find a mistake but I still get it wrong

To find the velocity after the collision I used the conservation of momentum equation above and calculated the "after impact) velocity to be -2/3 m/s. I then proceeded to find the acceleration and used Ax=-mew x g and got -2.94 m/s^2. From there I solved for time by plugging the velocity and acceleration into Vfx=Vix+Ax(delta T). I got the time for

the slide to be .22 seconds. I then plugged everything into the distance kinematics equation Xf=...and I got .075 m which I then converted to 7.55 cm, but it still says its wrong. Do you see any mistakes I made?