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
The most probable reason why the magnets won't stick on the refrigerator is that the body of the refrigerator and the magnets have like poles. If both have negative or both have positive poles facing each other, they will repel. In principle, magnets are attracted to opposite poles and like poles repel.
In the modern model of the atoms over 99.9℅ of the atom is made up of empty space
It depends on Mass and velocity
624 = 6(7x-1)
104=7x-1
105=7x
x= 15cm