Question

A rocket initially at rest on the ground lifts off vertically with a constant acceleration of 2.0 Ã 101 meters per second2 . how long will it take the rocket to reach an altitude of 9.0 Ã 103 meters?

Answer 1

Time taken, t = 30 seconds

Step-by-step explanation:

It is given that,

Initial speed of the rocket, u = 0

It is lifted with a constant acceleration of,
`a=2* 10^1\ m/s^2=20\ m/s^2`

Height to be attained,
`d=9* 10^3\ m`

Let t is the time taken by the rocket to reach an altitude of
`9* 10^3\ m`. Using the second equation of kinematics to find it as :

`d=ut+(1)/(2)at^2`

`d=(1)/(2)at^2`

`t=\sqrt{(2d)/(a)}`

`t=\sqrt{(2* 9* 10^3)/(20)}`

t = 30 seconds

So, the time taken by the rocket to reach given height is 30 seconds. Hence, this is the required solution.