Question

A weight lifter jerks 220 kg vertically through 1.5meters and holds still at that height for two minutes. The works done by him in lifting and in holding it still are respectively

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

Answer 1

The correct option is B 3234 J, 0

Work done in order to jerk the weight up is given by $w_1=m\times g\times s=220\times 9.8\times 1.5$ where g=9.8 is the acceleration due to gravity., m is the mass of the body/weight and s is the distance it has moved through due to the application of an external force.

Work was done in order to hold the mass at that height$=w_2=0$since the mass has not moved through any distance.