Question

A model rocket accelerates upward from the ground with a constant acceleration, reaching a height of 50 m in 8 s.a) What is the speed (in m/s) at a height of 50 m?A: 1.07×101 B: 1.25×101 C: 1.46×101 D: 1.71×101 E: 2.00×101 b) What is the acceleration (in m/s 2)?A: 1.56 B: 1.83 C: 2.14 D: 2.50 E: 2.93

Answer 1

Explanation:

It is given that, a model rocket accelerates upward from the ground with a constant acceleration, u = 0

Height reached, d = 50 m

Time taken, t = 8 s

Let a is the acceleration of the rocket. It can be calculated using second equation of motion as,

$d=ut+\dfrac{1}{2}at^2$

$a=\dfrac{2d}{t^2}$

$a=\dfrac{2\times 50}{8^2}$

$a=1.56\ m/s^2$

Let v is the speed at the height of 50 meters. So,

$v=u+at$

$v=at$

$v=1.56\times 8$

v = 12.48 m/s

or $v=1.25\times 10^1\ m/s$

Hence, this is the required solution.