The gravitational potential energy of the object falling from 18 m height is 36 J. Thus, its mass is 0.2 Kg.
Gravitational potential energy of an object is the energy generated by virtue of its position in a gravitational field. The magnitude of gravitational potential energy is directly proportional to the mass of the object , height from the surface and the acceleration due to gravity.
GPE = mgh
The height of the object falling = 18 m
Gravitational potential energy = 36 J
Acceleration due to gravity in earth = 9.8 m/s².
Mass of the object = GPE/ (gh)
= 36 J/ (18 m×9.8 m/s² )
= 0.20 Kg.
Therefore, the mass of the object is 0.20 Kg.
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b. What was Oliver’s power in watts?
Answer:
b. Decreases
Explanation:
The total resistance of a series circuit is equal to the sum of the individual resistances:
(1)
Therefore, as we add more lamps, the total resistance increases (because we add more positive tems in the sum in eq.(1).
The current in a circuit is given by Ohm's law:
where V is the voltage provided by the power source and is the total resistance. We notice that the current, I, is inversely proportional to the total resistance: therefore, when more lamps are added to the series circuit, the total resistance increases, and therefore the current in the circuit decreases.