Answer: question 1 , would be one question 2 , would be 1 joule and number three would be number one and number four would be , power and last one would be, number two
Explanation: sorry if its wrong
Answer:
In an ideal pulley system is assumed as a perfect system, and the efficiency of the pulley system is taken as 100% such that there are no losses of the energy input to the system through the system's component
However, in a real pulley system, there are several means through which energy is lost from the system through friction, which is converted into heat, sound, as well as other forms of energy
Given that the mechanical advantage = Force output/(Force input), and that the input force is known, the energy loss comes from the output force which is then reduced, and therefore, the Actual Mechanical Advantage (AMA) is less than the Ideal Mechanical Advantage of an "ideal" pulley system
The relationship between the actual and ideal mechanical advantage is given by the efficiency of the pulley system as follows;

Explanation:
Answer:
The Hydrostatic force is 
The location of pressure center is
Explanation:
From the question we are told that
The height of the gate is 
The weight of the gate is 
The height of the water is 
The density of water is 
Note used
for height of water and height of gate immersed by water since both have the same value
The area of the gate immersed in water is mathematically represented as

substituting values


The hydrostatic force is mathematically represented as

Where


So


The center of pressure is mathematically represented as

Where
is the moment of inertia of the gate which mathematically represented as

The
is the height of gate immersed in water
Thus


A advantage is less car accidents and a disadvantage is, in order to keep the roads clear of ice is a chemical. Like salt. Which is bad for the animals.
The work done is equal to the change in potential energy which is:
P.E = mgh
P.E = 500 x 9.81 x 15
P.E = 73,575 J
Power = work / time
Power = 73,575 / 20
Power = 3,700 Watts