Question

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? Question 30 options: She doesn't lose any because mechanical energy is always conserved. 5,880 J 3,000 J 2,880 J

Answer 1

The answer is 2,880 Joules.

Answer 2

Answer : The correct option is, 2880 J

Solution :

According to the question,

K.E + Energy lose to friction = P.E

`\text{Energy lose to friction}=P.E-K.E\\\\\text{Energy lose to friction}=mgh-(1)/(2)mv^2=m(gh-(1)/(2)v^2)`

where,

m = mass of object = 60 Kg

g = acceleration due to gravity =
`9.8m/s^2`

h = height = 10 m

v = velocity of an object = 10 m/s

Now put all the given values in the above formula, we get the energy lost to friction.

`\text{Energy lose to friction}=60Kg* (9.8m/s^2* 10m-(1)/(2)* (10m/s)^2)=2880\text{ Kg }m^2/s^2=2880J`

Therefore, the amount of energy she lose to friction is, 2880 J