Question

A block of mass $2kg$ is free to move along the X-axis. It is at rest and from $t=0$ onwards it is subjected to a time-dependent force F(t) in the x direction. The force F(t) varies with t. the kinetic energy of the block after 4.5 second is?

Answer 1

$m=\frac { -4 }{ 3 } $m=−43

$m=\frac{-4}{3}$

$Att=4.5sec$ F⃗ F→ = – 2N

Total Impulse I=[12x3×4]−[12×2×1.5]I=[12×3×4]−[12×2×1.5]

⇒ = 6 – 1.5 = 4.5 SI unit

Impulse = change in momentum

$4.5=2[v–0]$

v=4.52=2.25m/secv=4.52=2.25m/sec

K.E.=12×2×(2.25)2=5.06 J