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 falls freely from a height of $180 \,m$ onto a hard horizontal floor and repeatedly bounces. If the coefficient of restitution is $0.5$, the average speed and average velocity of the ball before it ceases to rebound are respectively (acceleration due to gravity $= 10 \,ms^{-2}$)

Morning breakfast provides $5000 \,cal$ of energy to a $60 \,kg$ person. The efficiency of the person is $30 \%$. The height up to which the person can climb using the energy obtained from the breakfast is ......... $m$.

$A$ mass of $1 \; kg$ collides elastically with a stationary mass of $5 \; kg$. After the collision,the $1 \; kg$ mass moves in the opposite direction with a velocity of $2 \; ms^{-1}$. Which of the following statements is correct for this system of two masses?

Vedclass Test Series

Exam Paper Generator

Online Exam Module