Answer:
The force is 
Explanation:
The diagram for this question is shown on the first uploaded image
From the question we are told that
The weight of the gate is 
The vertical component of F is 
From the diagram , taking moment about the pivot we have

Where
is the weight of the gate evaluated as

=> 
=> 
=> 
Answer:
D. Sound Energy, Magnetic energy
Explanation:
Sound energy is in motion, and Magnetic energy is about to be in motion.
Answer:
(4) weight
Explanation:
The centripetal force acting on the space shuttle in orbit is given by:

where
m is the mass of the shuttle
v is the tangential speed of the shuttle
r is the radius of its circular orbit
When the shuttle orbits the Earth, the centripetal force that keeps the shuttle in circular motion is given by the gravitational attraction between the shuttle and the Earth, which corresponds to the weight of the shuttle, and it is given by:

where
G is the gravitational constant
M is the Earth's mass
And this force, therefore, corresponds to the centripetal force.
I have no idea I need the answer too