A particle is projected vertically upwards wi | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) Let $W_f$ be the work done by air resistance during the upward journey. Since the work done by air resistance is the same for both paths,the work

Vedclass · Accepted Answer

$8$

Vedclass · Answer

(A) Let $W_f$ be the work done by air resistance during the upward journey. Since the work done by air resistance is the same for both paths,the work done during the downward journey is also $W_f$.Applying the Work-Energy Theorem for the upward journey from the point of projection to the maximum height $H$:$W_g + W_f = \Delta KE$$-mgH - W_f = 0 - \frac{1}{2}m(16)^2$$mgH + W_f = 128m$  --- $(1)$Applying the Work-Energy Theorem for the downward journey from the maximum height $H$ back to the point of projection:$W_g + W_f = \Delta KE$$mgH - W_f = \frac{1}{2}m(8)^2 - 0$$mgH - W_f = 32m$  --- $(2)$Adding equations $(1)$ and $(2)$:$2mgH = 160m$$2gH = 160$$2(10)H = 160$$20H = 160$$H = 8 \ m$.

Similar Questions

$A$ ball is thrown vertically downwards from a height of $20 \, m$ with an initial velocity $v_0$. It collides with the ground,loses $50\%$ of its energy in the collision,and rebounds to the same height. The initial velocity $v_0$ is .................... $m/s$ (Take $g = 10 \, m/s^2$)

$A$ locomotive of mass $m$ starts moving so that its velocity varies according to the law $v = k \sqrt{S}$,where $k$ is a constant and $S$ is the distance covered. Find the total work performed by all the forces acting on the locomotive during the first $t$ seconds after the beginning of motion.

$A$ ball is released from a height of $10 \, m$. If after the impact there is a loss of $40 \%$ in its energy,the ball shall rise up to ................. $m$.

Vedclass Test Series

Exam Paper Generator

Online Exam Module