Question

A force is applied to box of mass 4 kg and it changes the velocity from 3 m/s to 6 m/s in 8 s. Determine the work done by force during the this process.

• A. 27 J
• B. 54 J
• C. 72 J
• D. 96 J
• E. Cannot be determined from the information given

Answer 1

Answer: (B)

54 J

Work done $=$ change in kinetic energy

or $W=\frac{1}{2}m{v}_2^2-\frac{1}{2}m{v}_1^2=\left(0.5\right)\left(4\right)\left(6^2\right)-0.5\left(4\right)\left(3^2\right)=54J$