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A 40 kg-skier starts at the top of a 12-meter high slope. At the bottom, she is traveling 10 m/s. How much energy does she lose to friction? A.She doesn't lose any because mechanical energy is always conserved.
B.4,704 J
C. 2,000 J
D.2,704 J

Respuesta :

vincecaminita

2704 j is my answer i did the math. good luck

Answer : Lost energy, E = 2704 J

Explanation :

Given that,

Mass of the skier, m = 40 kg

Height from bottom, h = 12 m

Velocity at the bottom, v = 10 m/s

At the top she will have potential energy and at the bottom she will have kinetic energy. Finding one by one :

Potential energy, P = m g h

P = 40 kg × 9.8 m/s² × 12 m

P = 4704 J

Kinetic energy, K = 0.5 × m v²

K = 0.5 × 40 kg × (10 m/s)²

K = 2000 J

Lost energy, E = P - K

E = 4704 J - 2000 J

E = 2704 J

The energy that is lost to friction is 2704 J.

So, the correct option is (D) " 2704 J "

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