Mechanical advantage is the amount by which a machine multiplies input force. It is a measure of the force amplification using a tool or machine system.
Answer:
Work done to pull the piano upwards is 401250 J
Explanation:
Work is done against the gravity to pull the piano upwards
So here we can say that work done is

here we know that

also we know that
H = 75 m
now we have


Explanation:
Reactants ⇒ product + heat (exothermic reaction) ....(1)
We have given that the reaction is exothermic, so the heat is rejected from the reaction. We know that heat is the form of energy.
From equation (1)
from the given equation we can see that reactants have more energy than products.
So the reactants have higher potential energy in comparison to the products.