Answer:
Explanation:
Conservation of momentum
In the x direction
2(15) + 2(-10) = 2(-5) + 2(vBfx)
vBfx = 10 m/s
In the y direction
2(30) + 2(5) = 2(20) + 2(vBfy)
vBfy = 15 m/s
vBf = 10i + 15j
KEi = ½(2)(15² + 30²) + ½(2)(-10² + 5²) = 1250 J
KEf = ½(2)(-5² + 20²) + ½(2)(10² + 15²) = 750 J
KEf - KEi = 750 - 1250 = -500 J
