Answer:B
Explanation:
Given
First motor has three times as much as power as another
Let the power of smaller motor be P
Therefore bigger motor has power 3 P
and we know that energy 
Larger motor 
Smaller motor 
Therefore smaller motor will do same work if it takes three times the time taken by Larger motor
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
B) lever and pulley is the answer
Answer:
True
Explanation:
The bigger an object is, the more force you must apply to move the object. Think about it like moving a mouse compared to moving an elephant. You can't move the elephant by yourself, because you don't have enough strength or force to move it. But, you can easily pick up a mouse, because it requires less force, or strength. Hope this helped :)
It will move to the right and most likely a tiny bit down