Question

a block of mass 2 kg is moving along +x axis with speed 1m/s. A time dependent force f=(4-t)N starts acting along the axis. find k.e of block at t=6s​

Answer 1

Answer:

16 J

Explanation:

f=(4-t) N in +X axis

ma=(4-t) N

2*a=(4-t) N

a=(2-t/2) m/s² in +X Axis

we know,

a=dv/dt=(2-t/2)

dv=(2-t/2) dt

integrating both sides from t=0 to t=6 s

=>v at 6s - v at 0s=[2t-1/4t²]

=>v at 6s- 1=2*6-1/4*(6)²

=>v at 6s=4 m/s²

thus,the k.e at 6s=1/2*2*(4)² [k=1/2mv²]

=>16 J(answer)