12.13 Work and Power

Front

What is the definition of work in physics?

Back

Work is defined as the product of the force applied to an object and the distance over which that force is applied, in the direction of the force. It is calculated using the formula: Work (W) = Force (F) × Distance (d) × cos(θ), where θ is the angle between the force and the direction of motion.

Front

What is the unit of work in the metric system?

Back

The unit of work in the metric system is the Joule (J).

Front

What is the definition of power in physics?

Back

Power is the rate at which work is done or energy is transferred over time. It is calculated using the formula: Power (P) = Work (W) / Time (t).

Front

What is the unit of power in the metric system?

Back

The unit of power in the metric system is the Watt (W), which is equivalent to one Joule per second (1 W = 1 J/s).

Front

How do you calculate power if you know the work done and the time taken?

Back

Power can be calculated using the formula: P = W / t, where P is power, W is work done, and t is the time taken.

Front

If a machine does 500 Joules of work in 10 seconds, what is its power output?

Back

50 Watts.

Front

What is the formula for electrical power in terms of voltage and current?

Back

The formula for electrical power is: P = V × I, where P is power, V is voltage, and I is current.

Front

A light bulb has a power rating of 60 Watts and operates at a voltage of 120 Volts. What is the current flowing through the bulb?

Back

0.5 Amperes.

Front

What is the relationship between power, voltage, and current in an electrical circuit?

Back

Power (P) is directly proportional to both voltage (V) and current (I). The relationship is given by the formula: P = V × I.

Front

What is the formula for calculating work done when a force is applied at an angle?

Back

The formula is: W = F × d × cos(θ), where W is work, F is force, d is distance, and θ is the angle between the force and the direction of motion.