A sports car weighing 600 kg travels North at 35 m/s. Running a stop sign, the car crashes into a 2000 kg truck traveling East at 20 m/s. The vehicles become locked together and travel 18 meters before stopping. Find the direction and the deceleration of the wreckage from the point of impact. Can you show an example of how to find this?

Question

A sports car weighing 600 kg travels North at 35 m/s.  Running a stop sign, the car crashes into a 2000 kg truck traveling East at 20 m/s.  The vehicles become locked together and travel 18 meters before stopping.  Find the direction and the deceleration of the wreckage from the point of impact.  Can you show an example of how to find this?

bobpursley · Answer

momentum:
600*35N+2000*20E=(2600)@theta
momentum is conserved in all directions:
East Theta measured from N
2000*20=2600*VsinTheta
North
600*35=2600 V cosTheta

divide N equation into East equation
40000/600*35=TanTheta
solve for Theta.
Next, ust that angle to solve for V in either equation.
then
Vf^2=0=V^2+2a*18 solve for a.
and a is in the opposite direction from V