Question

(DUE IN 1 HOUR) A rocket of mass m is launched straight up with thrust F⃗ thrust.

Answer 1

From the statement, since rocket was launched so this means that it start from zero, hence initial velocity is zero. 
Since the rocket was launched vertically straight up, the force acting on this motion is gravity.

 
A. The acceleration of the motion is then given by:

a= F/m - g 

Then we can use the general equation:

V^2 = Vo^2 + 2*a*h

where V is final velocity, Vo is initial velocity, a is acceleration, h is height 

Since we know that Vo = 0, so 

V^2 = 2*a*h 

V^2 = 2 (F/m – g) h
V = sqrt [2 h (F/m – g)]

 

 

B. Given that:

h = 86 m

F = 10 N

m = 340 g = 0.34 kg

Find for V:

 

V = sqrt [2 * 86 (10 / 0.34 – 9.8)]

V = 58.08 m/s