Answer:

Explanation:
Given that:
- mass of 1 skier,

- inclination of hill,

- length of inclined slope,

- time taken to reach the top of hill,

- coefficient of friction,

<em>Now, force normal to the inclined plane:</em>



<em>Frictional force:</em>



<em>The component of weight along the inclined plane:</em>



<em>Now the total force required along the inclination to move at the top of hill:</em>



<em>Hence the work done:</em>



<em>Now power:</em>



<u>So, power required for 30 such bodies:</u>




-- Kinetic energy is the energy of mass in motion. The amount is determined by the mass of whatever is moving, and its speed.
-- Potential energy is the energy that's stored up in some form, not being used yet but ready to be used when you want it.
For example, one form of it is <u><em>chemical</em></u><em> </em>potential energy, like in a battery, or a match. You get the energy out of a battery when you connect it to a motor or a light. You get the energy out of as match when you make the tip hot and it flares up.
This question is asking about <u><em>gravitational</em></u> potential energy. An object has stored energy just by being up high, like a bowling ball on a shelf. You get the energy out of it just by dropping it ... possibly enough to crack the floor !
The amount of this kind of potential energy is determined by the mass of the object, and how high up it is.
-- Getting the answers from other people doesn't help you a bit, until you understand them and can answer the question on your own.
Eaither D or A bit I am leaning more towards D
Answer:
76 m /s
Explanation:
maximum height, H = 19.7 m
Angle of projection, θ = 15 degree
Let u be the projectile launch speed
Use the formula of maximum height


u = 75.9199 = 76 m /s