Answer:
6.75 seconds
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration = 16 m/s²
g = Acceleration due to gravity = 9.81 m/s²
Let y be the distance the rocket is accelerating
960-y is the distance traveled in free fall

In free fall

The distance the rocket will keep accelerating is 364.881828749 m
After which it will travel 960-364.881828749 = 595.118171251 m in free fall

The time the rocket is accelerating is 6.75 seconds
Let, 1st force = a
2nd force = b
A.T.Q,
a+b = 10
a-b = 6
Calculate for a & b, you'll get a=8 & b= 2
After increasing by 3, it'll be a = 8+3 = 11 & b=2+3 = 5
Resultant force at 90 degree angle = 11+5 = 16 Newtons