F a light bulb produces 60.0 J of electrical energy and is 45% efficient, how much energy does it use?
2 answers:
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Answer:
the ratio of Hank's mass to Harry's mass is 0.7937 or [ 0.7937 : 1
Explanation:
Given the data in the question;
Hank and Harry are two ice skaters, since both are on top of ice, we assume that friction is negligible.
We know that from Newton's Second Law;
Force = mass × Acceleration
F = ma
Since they hold on to opposite ends of the same rope. They have the same magnitude of force |F|, which is the same as the tension in the rope.
Now,
Mass × Acceleration
= Mass
× Acceleration
so
Mass / Mass
= Acceleration
/ Acceleration
given that; magnitude of Hank's acceleration is 1.26 times greater than the magnitude of Harry's acceleration,
Mass / Mass
= 1 / 1.26
Mass / Mass
= 0.7937 or [ 0.7937 : 1 ]
Therefore, the ratio of Hank's mass to Harry's mass is 0.7937 or [ 0.7937 : 1 ]
Answer:
The factor of the diameter is 0.95.
Explanation:
Given that,
Power of old light bulb = 54.3 W
Power = 60 W
We know that,
The resistance is inversely proportional to the diameter.
The power is inversely proportional to the resistance.
We need to calculate the factor of the diameter of the filament reduced
Using relation of power and diameter
Put the value into the formula
Hence, The factor of the diameter is 0.95.