24 !
a 60-kg skier starts at the top of a 10-meter high slope. at the bottom, she is traveling 10 m/s. how much energy does she lose to friction?

Potential Energy (Initial one) = m * g * h
P.E. = 60 * 9.8 * 10
P.E. = 5880

Kinetic Energy (Final One) = 1/2 mv²
K.E. = 1/2 * 60 * (10)²
K.E. = 6000/2
K.E. = 3000

Lost Energy = 5880 - 3000 = 2880 J

In short, Your Answer would be 2880 Joules

Hope this helps!