A 1800 Kg Car Is Moving At 30 M/S Eastward. It Collides Head On With A 2200 Kg Garbage Truck. What Is The Initial Velocity Of The Truck If The Car And

A 1800 kg car is moving at 30 m/s eastward. It collides head on with a 2200 kg garbage truck. what is the initial velocity of the truck if the car and the truck move together after collision at 12 m/s? 

 

Good Day....

Problem:

A 1800 kg car is moving at 30 m/s eastward. It collides head on with a 2200 kg garbage truck. what is the initial velocity of the truck if the car and the truck move together after collision at 12 m/s?

Note:

Total momentum of the system is conserved before and after collision. Therefore,

Total momentum (before collision) = Total momentum after collision

Given Data

                                   mass                       velocity (before collision)

car                           1800 kg                   30 m/s eastward

garbage truck        2200 kg                      v1 =    ? unknown

Solution:

Total momentum (before collision) = Total momentum after collision

(1800 kg × 30 m/s) + (2200 kg × v1) = (1800 kg × 12 m/s) + (2200 kg × 12 m/s)

     54000 kg.m/s  + (2200 kg × v1) = 21600 kg.m/s + 26400 kg.m/s

                                  (2200 kg × v1) = 48000 kg.m/s - 54000 kg.m/s

                                                    v1  = - 6000 kg.m/s / 2200 kg

                                                    v1 =  - 2.727 m/s

The velocity of the garbage truck before collision is = - 2.727 m/s since its direction is opposite to the direction of the car.

Hope it help...=)