Question

a 500g model rocket with a weight of 4.90 N is launched straight up. The small rocket burns for 5s and has a steady thrust of 20N. What maximum altitude does the rocket reach

Answer 1

The maximum height reached by the rocket at the given time is 377.5 m.

Step-by-step explanation:

Given;

mass of the rocket, m = 500 g = 0.5 kg

weight of the rocket, W = 4.9 N

Applied force or thrust of the rocket, F = 20 N

time of the rocket motion, t = 5 s

Apply Newton's second law of motion;

Applied force = Weight of the rock + Upward force of the rocket

F = W + ma

where;

a is the upward acceleration of the rock

`a = (F-W)/(m) \\\\a = (20 - 4.9)/(0.5) \\\\a = 30.2 \ m/s^2`

The maximum height reached by the rock during the given time is calculated as;

h = ut + ¹/₂at²

h = 0 + ¹/₂at²

h = ¹/₂at²

h = ¹/₂ (30.2)(5)²

h = 377.5 m

Therefore, the maximum height reached by the rocket at the given time is 377.5 m.