Question

Multiple constant forces $F_1,......F_i$ are acting on an object of mass 'm' and produce a displacement S, with an acceleration a. Which of the following statements is true.

• A. Work done on the object is ${\sum }_{i=1}^n\overrightarrow{F_i}.\overrightarrow{S}$
• B. Work done on the object is $\left({\sum }_{i=1}^n\overrightarrow{F_i}\right).\overrightarrow{S}$
• C. Work done on the object is $m\overrightarrow{a}.\overrightarrow{S}$
• D. If all the forces are acting in the same direction, then work done will be maximum

Answer 1

Answer: (A), (B), (C), (D)

The correct options are
A

Work done on the object is ${\sum }_{i=1}^n\overrightarrow{F_i}.\overrightarrow{S}$

B

Work done on the object is $\left({\sum }_{i=1}^n\overrightarrow{F_i}\right).\overrightarrow{S}$

C

Work done on the object is $m\overrightarrow{a}.\overrightarrow{S}$

D

If all the forces are acting in the same direction, then work done will be maximum

Work done by multiple forces is same as the summation of all the work done by individual forces. This is also same as the dot product of net force and displacement.