Question

A knife thrower throws a knife toward a 300-g target that is sliding in her direction at a speed of 2.30 m/s on a horizontal frictionless surface. She throws a 22.5-g knife at the target with a speed of 39.5 m/s. The target is stopped by the impact and the knife passes through the target. Determine the speed of the knife after passing through the target?

Answer 1

Obviously, energy cannot be conserved, so working with momentum...

+ direction away from her..

-300*2.30+22.5*39.5=300*0+22.5V

solve for V