Answer:
Explanation:
Given
Load 
height to which load is raised 
Another crane take
th time to lift the load
Energy required required to lift the Weight



Suppose
and
is the Power required to lift the weight in t and
time



thus

Second Crane requires 6 times more power than the slow crane
Answer:
Mechanical advantage is the measure of the force amplification achieved by using a tool , mechanical device or machine . ... So MA = 2 means that for example if you apply 100 N then your machine will multiply that force and generate 200 N..
Explanation:
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Substitution is The answer
Answer: 0.258
Explanation:
The resistance
of a wire is calculated by the following formula:
(1)
Where:
is the resistivity of the material the wire is made of. For aluminium is
and for copper is 
is the length of the wire, which in the case of aluminium is
, and in the case of copper is 
is the transversal area of the wire. In this case is a circumference for both wires, so we will use the formula of the area of the circumference:
(2) Where
is the diameter of the circumference.
For aluminium wire the diameter is
and for copper is 
So, in this problem we have two transversal areas:
<u>For aluminium:</u>

(3)
<u>For copper:</u>

(4)
Now we have to calculate the resistance for each wire:
<u>Aluminium wire:</u>
(5)
(6) Resistance of aluminium wire
<u>Copper wire:</u>
(6)
(7) Resistance of copper wire
At this point we are able to calculate the ratio of the resistance of both wires:
(8)
(9)
Finally:
This is the ratio