A hamster running on a wheel generated 180 J of work, but the hamster's power was only 10 W. How long did it take for the hamste
1 answer:
Answer:
18s
Explanation:
Given parameters:
Work done by hamster = 180J
Power of hamster = 10W
Uknown:
Time taken for the hamster to generate the work = ?
Solution:
Power can be defined as the rate at which work is being done by a body. It is related to both work done and time by the expression below;
Power =
Time taken =
Time taken = = 18s
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where
V is the potential difference across the electrical device
I is the current through the device
R is its resistance
For the heater coil in the problem, we know
and 
, therefore we can rearrange Ohm's law to find the current through the device:
(B) The resistance of a conductive wire depends on three factors. In fact, it is given by:
where
is the resistivity of the material of the wire
L is the length of the wire
A is the cross-sectional area of the wire
Basically, we see that the longer the wire, the larger its resistance; and the larger the section of the wire, the smaller its resistance.
where
V is the potential difference across the electrical device
I is the current through the device
R is its resistance
For the heater coil in the problem, we know
(B) The resistance of a conductive wire depends on three factors. In fact, it is given by:
where
L is the length of the wire
A is the cross-sectional area of the wire
Basically, we see that the longer the wire, the larger its resistance; and the larger the section of the wire, the smaller its resistance.