KCET 2025 Physics Paper

To determine the work done by the net force during the displacement of the body, we need to evaluate the change in kinetic energy ( △KE ) as the object moves from x=0 to x=2m.
The initial velocity u when x=0 is zero because v=kx3∕2 and substituting x=0 gives v=0.
The final kinetic energy at x=2m can be found by calculating the velocity at this point:
v=k⋅(2)3∕2
Given k=2 Sl units, the velocity at x=2 is:
v=2⋅23∕2
The change in kinetic energy is:
∆KE=‌

1

2

mv2−‌

1

2

mu2
Substituting m=0.25‌kg and u=0 :
∆KE=‌

1

2

×0.25×(2×23∕2)2−0
Calculate (2×23∕2)2 :
=(21×(23∕2))2=22×(23)=25=32
So the change in kinetic energy is:
∆KE=‌

1

2

×0.25×32
Finally, solving gives:
=4J
Hence, the work done by the net force during the displacement is 4 Joules.