In the formula \(W=Fs\cos\theta\), if the angle between force and displacement (θ) is less than 90°, the net work done by the force will be:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Positive
In \(W=Fs\cos\theta\), the force \(F\) and the displacement \(s\) are magnitudes and always positive, so the sign of the work is the sign of \(\cos\theta\).
For \(0^{\circ}\le\theta\lt90^{\circ}\), \(\cos\theta\) is positive, so the work is positive: the force has a part along the motion, as when a horse pulls a cart forward
At \(\theta=90^{\circ}\), \(\cos\theta=0\) and the work is zero
For \(\theta\gt90^{\circ}\), \(\cos\theta\) is negative and the work is negative, as for friction