Posted by shaquille on .
A 1,600 kg car traveling north at 10.0 m/s crashes into a 1,400 kg car traveling east at 15 m/s at an unexpectedly icy intersection. The cars lock together as they skid on the ice. What is their speed after the crash?

physics 
drwls,
Use conservation of momentum to get the north and east components of the final velocity, V. Then compute the resultant V, which will be the hypotenuse.
3000*Vy = 1600*10 = 16,000 kg m/s
3000*Vx = 1400*15 = 21,000 kg m/s
Vy = 5.333 m/s
Vx = 7.00 m/s
Speed = sqrt[Vx^2 + Vy^2] = 8.8 m/s
(Friction has been assunmed negligible becasue of the the ice.