JEE Main Physics question
A force of 5 N, making an angle θ with the horizontal, acting on an object displaces it by 0.4 m along the horizontal direction. If the object gains kinetic energy of 1 J, the horizontal component of the force is
Answer: (B)
Solution
By the work-energy theorem, (F cosθ) × s = ΔKE ⟹ F cosθ = 1/0.4 = 2.5 N, which is exactly the horizontal component of the force.