The work done will be equal to the potential energy of the piano at the final position
P.E=m.g.h
.consider the plank the hypotenuse of the right triangle formed with the ground
.let x be the angle with the ground=31.6°
.h be the side opposite to the angle x (h is the final height of the piano)
.let L be the length of the plank
sinx=opposite side / hypotenuse
= h/L
then h=L.sinx=3.49×sin31.6°=0.638m
weight w=m.g
m=w/g=3858/10=385.8kg
Consider Gravity g=10m/s2
then P.E.=m.g.h=385.8kg×10×0.638=2461.404J
then Work W=P.E.=2451.404J
Answer:

Explanation:
The bike's acceleration can be found by using the following suvat equation:

where
v is the final velocity of the bike
u is the initial velocity
a is the acceleration
s is the distance covered
For the bike in the problem,
u = 0
v = 7 m/s
d = 40 m
Solving the equation for a, we find the acceleration:

Answer:
for every action thete is an equal and opposite reaction
The first law of thermodynamics states the conservation of energy and heat where the total energy in an isolated system may be transformed into another, but never created or destroyed. If 314 J of energy was released to the room, then also 314 J of energy was also removed from food in that refrigerator assuming it is an isolated system. <span>
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