Final answer:
A watt is a measure of power, representing the rate of energy use, measured in joules per second; a 100-watt bulb uses 100 J of energy each second. Power is calculated by dividing work by the time taken to perform that work.
Step-by-step explanation:
Understanding Watts and Power
A watt (W) is the SI unit of power, which is defined as the rate at which energy is used or given off. A watt measures how much energy is expended in a certain amount of time. This is analogous to how calories burned during exercise can vary depending on the duration of the activity. When considering mechanical processes or electrical devices, power is an essential concept.
The watt is quantitatively measured in joules per second (J/s). For instance, a 100-watt light bulb uses energy at a rate of 100 joules per second. By multiplying power by time, we get the total amount of energy consumed, which is why electricity is sold in kilowatt-hours. The formula for power, P = W/t, indicates that power is equal to work W divided by the time t taken to do the work.
Understanding the watt is crucial for grasping how energy transfer works and for calculating the energy consumption of various devices we use in everyday life.