Q.

A body of mass 2 kg is moving along x-direction such that its displacement as function of time is given by x(t)=αt2+βt+γm, where α=1 m/s2, β=1 m/s, γ=1 m . The work done on the body during the time interval t=2 s to t=3 s is ______ J.   [2026]

1 42  
2 49  
3 12  
4 24  

Ans.

(4)

x(t)=t2+t+1

v(t)=2t+1

a(t)=2

F=4 N

Displacement=x(3)-x(2)

=13-7=6 m

W=F·S=4×6=24 J