A particle is projected vertically upwards with a speed of 16 m s- 1 , after some time, when it again passes through the point of projection, its speed is found to be 8 m s- 1 . It is found that the work done by air resistance is the same during upward and downward motion. Then the maximum height attained by the particle is -

Question

A particle is projected vertically upwards with a speed of 16 m s- 1 , after some time, when it again passes through the point of projection, its speed is found to be 8 m s- 1 . It is found that the work done by air resistance is the same during upward and downward motion. Then the maximum height attained by the particle is - (A) 8 m (B) 4.8 m (C) 17.6 m (D) 12.8 m

Tardigrade Admin · Accepted Answer

From work energy theorem for upward motion, (1/2)m (16)2=mgh+W for downward motion (1/2)m (8)2=mgh - W h=8 m

$8 m$

$4.8 m$

$17.6 m$

$12.8 m$

From work energy theorem
for upward motion,
$\frac{1}{2} m (16)^{2} = m g h + W$
for downward motion
$\frac{1}{2} m (8)^{2} = m g h - W$
$h = 8 m$

8m

4.8m

17.6m

12.8m

From work energy theorem for upward motion, 21​m(16)2=mgh+W for downward motion 21​m(8)2=mgh−W h=8m

$8 m$

$4.8 m$

$17.6 m$

$12.8 m$

From work energy theorem
for upward motion,
$\frac{1}{2} m (16)^{2} = m g h + W$
for downward motion
$\frac{1}{2} m (8)^{2} = m g h - W$
$h = 8 m$