In: Physics
Q1.(A)
ANS- Power of the process is , P= work done /time = mgh/t= (80*9.8*600)/4 =117600Watt
So, Power of the process is 117600Watt.
(B)
ANS- From conservation of energy-
total energy at top = total energy at bottom
P.Ei + K.Ei. = P.Ef + K.Ef
mgh + 0 = 0 + mv^2 /2
v= sqrrt(2gh)= sqrrt(2*9.8*600) =108.44 m/s
So, speed at the base of mountain is 108.44 m/s.
(C)
Ans- Assumptions- Friction, air resistance and any other non conservative forces are not present.
speed will be less if we measure it experimentally , since in reality there is friction force acting on Trex and air resistance hence some energy will be lost there and hence t rex will have less energy than what we calculated .