JEE Main202224 Jun 2022Morning ShiftPhysicsWork, Power and EnergyActual
A particle experiences a variable force F → = 4 x i ^ + 3 y 2 j ^ in a horizontal x - y plane. Assume distance in meters and force is newton. If the particle moves from point 1 , 2 to point 2 , 3 in the x - y plane, then Kinetic Energy changes by :
Options
- A25   J
- B50   J
- C12 . 5   J
- D0   J
Correct answer
A. 25   J
Step-by-step solution
Using Work energy theorem, Kinetic energy ∆ K E = W = ∫ 1 2 4 x d x + ∫ 2 3 3 y 2 d y = 4 x 2 2 1 2 + 3 y 3 3 2 3 = 2 × 2 2 - 2 × 1 2 + 3 2 - 2 3 = 6 + 19 = 25 Joules