Question

A weight lifter jerks $220kg$ vertically through $1.5meters$ and holds still at that height for two minutes. The work done by him in lifting and in holding it still are respectively (Take $g=9.8m/s$):

• A. $220J,330J$
• B. $3234J,0$
• C. $2334J,10J$
• D. $0,3234J$

Answer 1

Answer: (B)

$3234J,0$

Work done by weightlifter in lifting$=mgh$
work $=220\times 9.8\times 1.5=3234J$.
In second case, Displacement=0. Therefore, work =0.