A 6 kg body moves according to x=t²/4 metres, where t is measured in seconds. Find work done by resultant force during first 2 seconds (J).
Physics · Mixed Chapter
JEE Main Practice

Question

A 6 kg body moves according to x=t²/4 metres, where t is measured in seconds. Find work done by resultant force during first 2 seconds (J).

G1 Physics · Accepted Answer

Step 1: Velocity v=dx/dt=t/2. Thus initially v₀=0 and at t=2 s, v=1 m/s. Step 2: Work–energy theorem W=ΔK=½m(v²−v₀²). Step 3: W=½×6×(1−0)=3 J.