Energy Flashcards
What is kinetic energy?
The energy stored by an object’s movement
What is Elastic energy?
The energy stored when an object is being stretched or squashed
What is gravitational potential energy?
Why does it exist?
- The energy stored in objects raised above the Earth’s surface
- This energy exists because of the Earth’s gravitational field
What is internal energy?
The sum of the kinetic and chemical energy of the particles that make up an objects
What is nuclear energy?
The energy stored in the nucleus of an atom
What is chemical energy?
The energy stored by chemical bonds between atoms
What is the equation for G.P.E?
GPE (J) = Mass (Kg) x GFS (N/Kg) x Height (M)
What type of energy do you gain when you eat food?
Chemical
Name some examples of energy conversion…
- Bringing water to a boil in an electric kettle
- An object accelerated by a constant force
- A vehicle slowing down
- An object projected upwards
- A moving object hitting an obstacle
What can never happen to energy?
- Be created
- Be destroyed
Name the 6 key types of energy…
- Chemical
- Elastic potential
- Nuclear
- Internal
- Kinetic
- Gravitational potential
Where does chemical energy come from?
Comes from the potential energy stored in the bonds between particles
Where does kinetic energy come from?
- Comes from the random motion of the particles
- The temp of a body (object) is a measure of the kinetic energy of its particles
- Increasing a body’s temp increases the kinetic energy of the body’s particles, increase in the body’s internal energy
What two types of energy are internal?
- Kinetic
- Chemical
What is Gravitation potential energy measure in?
Joules (J)
Which of these has the larger kinetic energy assuming they are traveling at the same velocity?
Mouse or Elephant
Cat or Rhinoceros
Guinea pig or Dog
Elephant
Rhinoceros
Dog
If the mass of an object is 2kg, the gravitational field strength is 4 and the change in height is 2m, what is the change in GPE (gravitational potential energy)?
16 J
Where does the chemical energy that contributes to internal energy come from?
The potential energy stored in the bonds between particles
Name 4 method of energy conversion…
- Heating
- Electrical work
- Mechanical work
- Waves
What does heating increase?
An objects internal energy (Which is the sum of the kinetic and chemical energy of its particles)
What is electrical work?
When an electrical current transfers energy from one object to another
What is mechanical energy?
When energy is transferred from one object to another via a force
What are waves?
Structures that can transfer energy from one object to another e.g. Light and sound
Which principle tells us that energy cannot be created or destroyed?
Conservation of energy
What is the equation for work done?
Work done = force x distance (moved along the line of action of the force)
More work is done if you:
- push with the same force for a longer distance
- or push with a larger force for the same distance
The work done by a force is equal to…
the energy transferred to the object.
A book is pushed 10cm along a desk by applying a force of 8N. What is the work done on the book?
- Remember the equation for work done
W = F × d - Convert to correct units
10 cm = 0.1 m - Substitute the values in.
W = 8 N × 0.1 m - Calculate work done
W = 0.8 J
Which of these quantities is considered in the equation for work done?
- Speed
- Force
- Time
- Mass
Force
What is the electrical energy transferred to a component with a power rating of 10W is switched on for 4s?
- Remember the equation for electrical energy
E = P t - Substitute the values in
E = 10 × 4 - Answer
E = 40 J
What Is the equation for electrical work - Work done when a current
E=VIt
Energy = Potential difference x current x time
What is the charge for electrical current?
energy=charge×potential difference
A book is pushed 60cm along a desk by applying a force of 12N. What is the work done on the book?
- Remember the equation for work done
W = F × d - Convert to correct units
60 cm = 0.6 m - Substitute the values in.
W = 12 N × 0.6 m - Calculate work done to appropriate number of significant figures
W = 7.2 J
What is the electrical energy transferred to an component when a charge of 3C passes through a potential difference of 2V?
- Remember the equation for electrical energy
E = Q V - Substitute the values in.
E = 3 × 2 - Answer
E = 6 J
What is the equation for power?
Power (W) = work done (J) divided by Time (S)
- Power is the rate of energy transfer (or work done).
Power is the rate of…
Energy transfer
What is power?
- Power is the rate of energy transfer (or work done). The faster that energy is transferred (or work is done), the higher the power.
- Power (P) is the rate of energy transfer to a component. This is the same as saying power is the energy transferred per second. It is also equal to the rate at which work is done.
The ………. done by a force is equal to the ……….. transferred to the object.
- work
- energy
The faster that energy is transferred (or the faster work is done), the …………. the power.
- higher
When one type of energy is converted into another type of energy, some energy is …………….. (transferred into unwanted types of energy).
- wasted
what is the equation for the Efficiency of an energy transfer?
efficiency of energy transfer (%) = useful energy output (J) divided by total energy input (J) ×100
How is efficiency most often expressed?
As a percentage
Name 4 types of thermal insulation and why they are used…
- Loft insulation (The roof)
- Double glazing (Windows)
- Cavity walls insulation (Walls)
- Carpets (Floors)
because heat is lost through these places