The correct answer to your question here is D
One scientist proposes an idea and other scientists repeat his or her experiments so they can Accept the Idea.
Answer:
4086 J
Explanation:
The potential energy is transformed to kinetic energy less the frictional energy. Potential energy= mgh where m represent mass, g is acceleration due to gravity and h is the height of cliff
Since we have force of air resistance, work done due to air resistance will be product of force and distance

Substituting 10 Kg for m, 9.81 for g and 60 m for F then the kinetic energy at the bottom will be
KE= 10*9.81*60- (30*60)=4086 J
Answer:
Part a)
P = 13.93 kW
Part b)
R = 8357.6 Cents
Explanation:
Part A)
heat required to melt the aluminium is given by

here we have



Since this is the amount of aluminium per hour
so power required to melt is given by



Since the efficiency is 85% so actual power required will be

Part B)
Total energy consumed by the furnace for 30 hours



now the total cost of energy consumption is given as


