B
C
all did the same amount of work
Answer: all did the same amount of work
Explanation:
The work done by each mountain climber to climb the mountain is equal to how much gravitational potential energy they gained in the climb, and this is given by
where m is the mass of the climber, g is the gravitational acceleration, and is the gap in altitude.
Since the three climbers have same weight, they also have same mass, so the term "m" in the formula is the same. Also, they started from the same altitude and arrive at the same altitude, so the gap is the same for all of them. Therefore, they gain the same gravitational potential energy, and so they did the same amount of work. So, the work does not depend on the path taken.
-___________
Efficiency of a machine is defined as the ratio of work performed on it to work performed by it.
Efficiency = Output energy/ Input energy
The percentage value of efficiency of a machine is calculated as:
Efficiency = (Output energy/ Input energy) X 100%
Learn more about the machine efficiency with the help of the given link:
#SPJ2
A change in momentum
Newton's Third Law
The conservation of Momentum