Physics-(general)
NEET Physics (general) MCQ Question
Type: MCQ-numerical-Hard-Class 11
An object of mass m is initially at rest and is subjected to a varying force F(x) over a displacement from x_i to x_f. Considering the work-energy theorem, which of the following expressions correctly represents the final kinetic energy K_f of the object?
A
K_f = ∫[x_i to x_f] F(x) dx
B
K_f = mgh
C
K_f = 0.5mv^2 + ∫[x_i to x_f] F(x) dx
D
K_f = mgh - ∫[x_i to x_f] F(x) dx
Correct Answer
Option A
Detailed Explanation
The work-energy theorem states that the change in kinetic energy is equal to the work done. For a varying force, this is represented as K_f - K_i = ∫[x_i to x_f] F(x) dx, and since the object is initially at rest, K_i = 0, thus K_f = ∫[x_i to x_f] F(x) dx.
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