Question

A truck of 5000kg hits a car of 1500kg at an intersection. After the collision, both vehicles remained glued together and slid over a distance of 30 meters before coming to a halt. Knowing that the coefficient of kinetic friction between both vehicles and the street is 0.700, find the velocity of the truck before the collision.

Answer 1

The velocity immediately after contact is found by
1500*0+5000V=6500V'

So the energy after the collision in motion is 1/2 (6500)V'^2

that must equal (6500)g*mu*distance

1/2 6500 V'^2=6500 g*.7*30
or
V'^2=2g*.7*30

But V'=5000/6500 V
now put that in, and solve for V

Answer 2

how do you find this?

1500*0+5000V=6500V'

Thank you for your time