A block of mass $2\ kg$ 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 $t$ as shown in the figure. The kinetic energy of the block after $4.5$ seconds is [image:6_image24.emf]

Question

Dr. Abubacker · Accepted Answer

(c) $\int_{}^{}{Fdt = \mathrm{\Delta}ho}$
$\Rightarrow \frac{1}{2} 	imes 4 	imes 3 - \frac{1}{2} 	imes 1.5 	imes 2 = p_{f} - 0 \Rightarrow p_{f} = 6 - 1.5 = \frac{9}{2}$
$K.E. = \frac{p^{2}}{2m} = \frac{81}{4 	imes 2 	imes 2};K.E.\  = 5.06\ J$

Q. A block of mass $2\ kg$ 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 $t$ as shown in the figure. The kinetic energy of the block after $4.5$ seconds is

Explanation

Reviewed by Dr. Abubacker

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