Question

if a body is projected with of 20m/s speed in vertically upward find the maximum height reached,time of ascent and velocity after 2 seconds​

Answer 1

Answer:

Time of agent is 2seconds

velocity at w seconds is 0m/s

Explanation:

${v}^{2} - {u }^{2} = 2as$

v=final velocity=0m/s

u=intial velocity=20m/s

a=gravitational force 10m/s²

${0}^{2} - {20}^{2} = 2 \times - 10 \times s$

$0 - 400 = - 20s$

$\frac{ - 400}{ - 20} = s$

s=20meters

$s = ut + \frac{1}{2} a {t}^{2}$

$20 = 20 \times t + \frac{1}{2} ( - 10) {t}^{2}$

$20 = 20t - 5 {t}^{2}$

$5 {t}^{2} - 20t + 20 = 0 \\ {t}^{2} - 4t + 4 = 0$

•°•t=2 sec

$a = \frac{v - u}{t}$

at 2seconds

$- 10 = \frac{v - 20}{2} \\ - 20 = v - 20 \\ v = - 20 + 20 \\ v = 0 \frac{m}{s}$