Work, Energy & Power Concepts

What is the definition of work in physics?

Which of the following units is NOT equivalent to work?

If a force of 20N moves an object through 15m, how much work is done?

What is the formula to calculate work done when a force is applied at an angle?

How is the work done against gravity calculated when lifting a mass?

A boy runs up a staircase with 30 steps, where each step is 15cm high. If his mass is 80kg and g = 10 m/s², how much work is done by the boy?

When lifting a mass of 12kg through a distance of 1.25m with a force of 35N, what is the work done?

What information is needed to calculate work when a force is applied at an angle?

What is the formula for calculating work done?

Which type of energy is stored in the nucleus of atoms?

What is the unit of measurement for energy?

How is potential energy calculated?

If a body of mass 30 kg is lifted to a height of 5 m, what is its potential energy? (Use g = 10 m/s²)

What type of energy is characterized by a body in motion?

What is the potential energy of an object with a mass of 0.55 kg at a height of 14.2 m? (Use g = 10 m/s²)

If an object has a potential energy of 55 Joules and a mass of 15 kg, what is its height? (Use g = 10 m/s²)

Work, Energy & Power

Work: Work is done when a force moves an object through a distance. For work to occur, the force must be applied in the direction of the displacement.
Work Formula: Work = Force x Distance x cosθ, where θ is the angle between the force and the displacement
- Work is measured in Joules (J) or Newton-meters (Nm).
- Force is measured in Newtons (N).
- Distance is measured in meters (m).
Force: Force = mass x acceleration (F = ma)
Example Calculation: A force of 20N moves an object 15m. The work done is 300 Joules (20 N x 15 m = 300 J).

Different Forms of Energy

Energy: Energy is the ability to do work. It is measured in Joules.
Types of Energy:
- Chemical Energy
- Mechanical Energy (potential and kinetic)
- Nuclear Energy
- Sound Energy
- Hydro Energy
- Solar Energy

Potential Energy

Potential Energy: Energy stored in an object due to its position or configuration.
Gravitational Potential Energy (GPE):
- P.E. = mgh (mass x acceleration due to gravity x height)
- Example Calculation: An 80kg boy climbs 4.5m. GPE = 3600 J (80 kg x 10 m/s² x 4.5 m = 3600 J).

Kinetic Energy

Kinetic Energy: Energy an object possesses due to its motion (movement).
Kinetic Energy Formula: KE = 1/2mv² (one-half x mass x velocity²).
- Mass (m) is in kilograms (kg).
- Velocity (v) is in meters per second (m/s).
- Kinetic energy (KE) is in Joules (J).
Example Calculation: A 25kg car moving at 15 m/s has kinetic energy of 2812.5 J (1/2 x 25 kg x (15 m/s)² = 2812.5 J).

Test your understanding of work, energy, and power with this quiz. Explore the definitions, formulas, and different forms of energy, including potential and kinetic energy. This quiz covers essential concepts necessary for mastering physics.