A rocket weighs 1 x10^7 N while on the surface of the earth.
Theignition of its engines results in a lift off force of 1.5 X
10^7N

a) what is the mass of the rocket.
b) what is its acceleration at lift -off
c)How fast will it be moving if it acceleartion at this rates for10
minutes.
d) How high will it be after 10 minutes.

Respuesta :

Answer:

(a) [tex]1.02\times 10^{6}\ kg[/tex]

(b) a = [tex]4.9\ m/s^{2}[/tex]

(c) v' = 2940 m/s

(d) h = 1764 km

Solution:

As per the question:

Weight of the rocket, W = [tex]1\times 10^{7}\ N[/tex]

Lift-off force, F = [tex]1.5\times 10^{7}\ N[/tex]

Now,

To calculate:

(a) Mass of the rocket:

Calculate the mass from the weight of the rocket:

W = mg

where

m = mass of the rocket

Thus

[tex]m = \frac{W}{g} = \frac{1\times 10^{7}}{9.8} = []

(b) To calculate acceleration at lift-off:

F = m(g + a)

[tex]a + g = \frac{1.5\times 10^{7}}{1.02\times 10^{6}}[/tex]

a = 14.7 - g = 14.7 - 9.8 = [tex]4.9\ m/s^{2}[/tex]

(c) To calculate the velocity:

Use kinematic eqn:

v' = u + at

u = initial velocity = 0 m/s

v' = at = [tex]4.9\times 10\times 60 = 2940 m/s[/tex]

(d) To calculate the height, h:

Use kinematic eqn:

[tex]h = \frac{1}{2}gt^{2} = 0.5\times 9.8\times (10\times 60)^{2} = 1764000\ m = 1764\ km[/tex]