Question

A force F=3i^+2j^+cj^ N causes a displacement r=ci^+4j^+ck^ m. The work done is 36J. Find the
value(s) of c.

Answer 1

Answer: -7 , 4

Explanation:

we know that, Work done = force . displacement

since, work is a scaler quantity , we'll do dot product.

36 = (3i^ + 2j^ + ck^) . (ci^ + 4j^ + ck^)

36 = 3c + 8 + c^2

c^2 + 3c - 28 = 0

(c+7)(c-4) = 0

c=-7 and 4