Topic 1 - Energy Flashcards
What is a system?
A system is an object or group of objects.
What is a kinetic store?
The energy stored in an object’s movement.
What is a gravitational potential store?
The energy stored in objects raised above the Earth’s surface.
What is a chemical store?
The energy stored by the chemical bonds between atoms.
What is an elastic store?
The energy stored when an object is being stretched, compressed or squashed.
What is a nuclear store?
The energy stored in the nucleus of an atom. This energy can be released by radioactive decay.
What is an internal store?
The internal store of energy is the sum of kinetic energy stored in the particles of an object and the potential energy stored in chemical bonds between particles in the object. It is basically the energy stored by the particles that make up an object.
What is the temperature of a body a measure of?
The energy in the kinetic stores of its particles.
What happens to the energy stores if the temperature of the body increases?
The energy in the kinetic stores of the body’s particles increases, which means that the energy in the body’s internal store also increases.
What are the components of an object’s internal store?
The potential store and the kinetic store.
What happens when you eat food with energy?
Energy is added to your body’s chemical store. It is stored there until you need it.
What happens in order to allow an animal to move.
Energy stored in the chemical store, is transferred from it to the kinetic store.
What happens in order to make the body warm?
Energy stored in the chemical store, is transferred from it to the thermal store.
What is the formula for kinetic energy stored?
(Ek) = 1/2mv^2 - this is the same as Kinetic Energy Stored = 1/2 x mass x velocity^2 (squared).
What are the units for the formula of kinetic energy stored?
Joules (J) = 1/2 x Mass (kg) x Velocity^2 (m/s)
What is the formula for gravitational potential energy stored?
Δ(Ep) = mgΔh - this is the same as Change in Gravitational Potential Energy = mass x gravitational field strength x change in height.
What are the units for the formula of gravitational potential energy stored?
Joules (J) = Mass (kg) x GFS (n/kg) x Change in height (m)
What is the formula for elastic potential energy stored?
(Ee) = 1/2ke^2 = this is the same as Elastic Potential Energy Stored = 1/2 x spring constant x extension^2 (squared).
What are the units for the formula for elastic potential energy stored?
Joules (J) = 1/2 x Spring Constant (N/m) x Extension^2 (m)
What is the principle of the conservation of energy?
Energy cannot be created or destroyed. It can only be transferred from one store of energy into another.
How can electrical work transfer energy?
An electrical current transfers energy from one object to another, such as a battery powering a torch.
How can mechanical work transfer energy?
When energy is transferred from one object to another via a force.
How can mechanical work transfer energy when an object falls from a builiding?
The weight does mechanical work to transfer energy from the gravitational potential energy store to the kinetic store.
What happens with energy when a wheelchair is pushed?
Energy is transferred to the kinetic store of the wheelchair.
How can heating transfer energy?
Heating an object transfers energy to its internal store.
How can waves transfer energy?
Light and other types of waves can transfer energy to another.
Explain fully how a moving object hitting an obstacle transfers energy?
The object’s energy is in the kinetic store to begin with because it is moving. When the object collides with the obstacle, energy is converted to: the kinetic store of the obstacle (making it move) and the thermal store of the object and the obstacle (the particles in the object and the obstacle vibrate more). Some energy remains in the object’s kinetic store as it moves away after the collision.
How does boiling water in an electric kettle transfer energy?
Energy transfers from the electrical store of the mains power supply to the thermal store of the water.
How do objects accelerated by constant force transfer energy?
Work is done by a force on an object. This work is converted to the object’s kinetic store.
How does a vehicle slowing down transfer energy?
Starting off, the vehicle’s energy is in the kinetic store. The brakes do work slowing the car down. During this process, energy is lost through heat and sound.
How does an object being project upwards transfer energy?
The object’s energy is initially in the kinetic store as it moves upwards. The objects energy is slowly transferred into from the kinetic store to the gravitational potential store as it slows down and climbs higher. Once the object reaches its highest point, all of its energy is in the gravitational potential store. As the object falls again, energy transfers from the gravitational potential store to the kinetic store.
What is work done by a force?
Work done by a force is equal to the energy transferred to the object.
How is more work done?
Push with the same force for a longer distance, or push with a larger force for the same distance.
What is the formula for work done?
Work done = force x distance.
What are the units for the formula of work done?
Joules (J) = Newtons (N) x Distance (m)
What is the formula for work done when a current flows?
E = V x I x t - this is the same as energy = potential difference x current x time.
What is the formula for electrical energy?
E = Q x V - this is the same as electrical energy = charge x potential difference.