i think this is the incomplete page that you are showing but the answer is
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Answer: 37.5 kg in 3 s.f.
Explanation:
Answer:
C. Overcome Friction
Explanation:
When using any machine usually those with moving parts, you may notice heat forming near the areas where most movement occurs. As friction continues, more energy is used up and released as heat. For that reason, the efficiency of a machine will forever be less than 100%
Here as we know that there is no loss of energy
so we can say that maximum kinetic energy will become gravitational potential energy at its maximum height
So here we have

here we have
v = 20 m/s
m = 8000 kg
now from above equation we have



so maximum height is 20.4 m