A force F is applied to a body P as shown in the diagram above. If the body moves through a distance, a, which of the following represents the work done?
A
Fa
B
Fa Cos θ
C
\(\frac{Fa}{\cos \theta}\)
D
FaSin θ
E
\(\frac{Fa}{\sin \theta}\)
Verified Correct Answer: B.
Physical Principles & Numerical Solution
Resolving the Force F into x and y components;
\(F_x = Fcos\theta\)
\(F_y = Fsin\theta\)
but workdone = Force x distance.
therefore, work done = \(Fcos\theta \times a = FaCos \theta\)
Source: WAEC / JAMB / NECO Classroom Archive (Record #42958)