Question

IT'S URGENT PLZZZZZZZZZ HELP SOMEONE HELP PLZZZZZZZZZZZZZZZ I NEED IT PLZZZZZZZZZZZZZZZZZZ!!!

Answer 1

At start:   PE only

At end:  KE and energy lost to friction


PE = KE + E
E  = PE - KE
    = mgh - (1/2)mv^2
    = (40)(9.8)(12) - (.5)(40)(10)^2
    = 2704J