To determine the power output of an engine, we need to use the fundamental definition of power, which is the rate at which work is done. Power is calculated by dividing the total work done by the time taken to do that work.
Power (\(P\)) is defined as work done per unit time.
\[ P = \frac{W}{t} \]The unit Joule per second (J/s) is equivalent to Watt (W).
\[ P = 50 \text{ W} \]A) 50 W — The calculation shows that the power output is 50 W, which is obtained by dividing 500 J of work by 10 seconds.
This question tests the fundamental definitions of work and energy in physics. Understanding the relationship between these two concepts is crucial. Work is done when a force causes displacement, and this process involves a transfer or transformation of energy.
Correct Option: A) Work is a measure of energy transfer. This statement accurately describes the relationship between work and energy. When work is done, energy is transferred from one system to another or transformed from one form to another. The amount of work done is equivalent to the amount of energy transferred or transformed.
The question asks for the definition of power. We need to recall the fundamental definition of power in physics and compare it with the given options.
Where:
Alternatively, power can also be defined as the rate of energy transfer or energy used per unit time, as work done is a form of energy transfer.
C) Work done per unit time — This is the precise definition of power. It signifies how quickly work is performed or energy is converted.
The concept of work in physics is defined by the product of force and displacement in the direction of the force. Understanding this definition is key to determining when work is done on an object.
C) When a force is applied, causing displacement in the same direction as the force. This statement describes the condition where positive work is done, as \(\theta = 0^\circ\), leading to \(W = F \cdot d\).
This question tests the understanding of the principle of conservation of mechanical energy, especially in the context of free fall where air resistance is neglected.
Correct Option: D) Constant throughout the fall
This question relates to the fundamental definitions of power and work in physics. Power is the rate at which work is done. If power is constant, we can use the relationship between power, work, and time to determine how work done changes over time.
A) Increases with time. As derived from the formula \(W = P \times t\), if power \(P\) is constant, work \(W\) is directly proportional to time \(t\). Therefore, as time increases, the work done increases.