energy changes in a system

Define a system in physics.

A system is an object or group of objects that is being studied, often isolated to analyze energy transfers and transformations.

Give examples of energy changes in a system.

Examples include: 1. A battery storing chemical energy that is converted into electrical energy when used. 2. A spring compressing and storing elastic potential energy.

Describe energy changes during energy transfer.

Energy changes include heat transfer, work done on an object, or the flow of electric charge, which can alter the system's total energy.

Calculate changes in energy during heat transfer, work, or charge flow.

Use relevant equations to quantify energy changes based on parameters like heat, work, or charge movements.

Calculate kinetic energy.

The kinetic energy (E_k) of an object can be calculated using the formula: $E_k = \frac{1}{2}mv^2$ where m is mass and v is velocity.

Calculate elastic potential energy in a spring.

The elastic potential energy (E_e) stored in a stretched spring can be calculated using: $E_e = \frac{1}{2}ke^2$ where k is spring constant and e is extension.

Calculate gravitational potential energy gained by an object.

The gravitational potential energy (E_e) gained by an object raised to height h is given by: $E_e = mgh$ where m is mass, g is gravitational acceleration, and h is height.

Calculate energy changes with temperature variations.

The energy change (ΔE) with temperature change can be calculated using: $ΔE = mcΔθ$ where m is mass, c is specific heat capacity, and Δθ is the temperature change.

Define specific heat capacity.

Specific heat capacity is the amount of energy required to raise the temperature of 1 kilogram of a substance by 1 degree Celsius.

Investigation to determine specific heat capacity.

Practical experiments such as heating a material and measuring temperature change can be used to determine specific heat capacity.

Define power in physics.

Power is the rate at which energy is transferred or the rate at which work is done, measured in watts (1 watt = 1 joule/second).

Calculate power using equations.

Power (P) can be calculated with the formulas: $P = \frac{E}{t}$ and $P = \frac{W}{t}$ where E is energy transferred and W is work done.

Explain how power output can differ in energy transfer systems.

Two systems transferring the same amount of energy can have different power outputs if the time taken for the transfer varies.