4 energy respurces and transfers physics

What are the 8 main stores of energy?

Chemical, Kinetic, Gravitational, Elastic, Thermal, Magnetic, Electrostatic, Nuclear

What is meant by the conservation of energy?

Energy cannot be made or destroyed but can change from one form to another; the total amount of energy in a closed system remains constant.

What are the four main transfer types between energy stores?

Mechanically, Electrically, By heating, By radiation

How can energy be transferred through electrical equipment?

Energy is stored as chemical in the battery, then current converts chemical energy into other forms electrically.

How can energy be changed through work done by forces?

A force converts energy mechanically by work done, e.g., kinetic energy is converted to gravitational potential energy (GPE) when moving upwards.

What energy changes take place when a skateboarder goes down a hill?

Starts with GPE, converts to KE while riding down, and eventually all energy is lost as heat due to friction.

What equation is used to calculate the efficiency of a system?

Efficiency = (Useful energy output / Total energy input) × 100%

What energy changes are involved when a moving car stops?

Kinetic energy changes to heat energy (through friction) and sound energy.

What changes occur when a ball rolls down a hill?

Gravitational potential energy (GPE) turns into kinetic energy (KE) as it rolls downwards.

What is wasted energy?

Energy not used by the device for its intended purpose, e.g., sound energy from a kettle is waste energy.

In what ways can thermal energy be transferred?

Conduction, Convection, Radiation.

Why is the electrical heater of a kettle placed at the bottom?

Heat is mainly transferred by convection; heated liquid rises, creating a convection current.

How does the thickness of a building's walls affect the rate of cooling?

Thicker walls decrease the rate of cooling as heat has to travel further to escape.

How does thermal conductivity of walls affect the rate of cooling?

Higher thermal conductivity increases the rate of cooling as heat escapes more easily.

How can surfaces be adjusted for heat transfer by radiation?

Black, dull surfaces are good emitters/absorbers; white, shiny surfaces are good reflectors.

How can you reduce unwanted energy transfer?

Use insulation, double glazed windows, and curtains.

What equation is used to measure the work done on an object?

Work Done = Force × Distance

What is the relationship between work done on an object and energy transferred?

Work Done = Energy Transferred.

What equation is used to calculate the change in gravitational potential energy?

∆GPE = m × g × ∆h

What equation is used to calculate kinetic energy?

KE = ½mv²

What does 'power' mean in physics?

The rate at which energy is transferred; work done per unit of time.

What equation links work done, power, and time taken?

Power = Work Done / Time Taken

What is another way of describing a watt?

1 Watt = 1 joule per second (J/s).