Topic 8 - Energy and Forces doing Work Flashcards
(20 cards)
What is work done?
Work done is the transfer of energy when a force moves an object over a distance. It is measured in joules (J).
What is the equation for calculating work done?
Work done = Force × Distance moved in the direction of the force
What are the units of work done, force, and distance?
Work done: Joules (J)
Force: Newtons (N)
Distance: Meters (m)
What is kinetic energy?
Kinetic energy is the energy possessed by a moving object due to its motion. It depends on the mass and speed of the object.
What is the equation for kinetic energy?
Kinetic energy = 0.5 x mass x speed^2
What is gravitational potential energy (GPE)?
Gravitational potential energy is the energy stored in an object due to its position in a gravitational field, usually relative to the ground.
What is the equation for gravitational potential energy?
Gravitational potential energy = Mass × Gravitational field strength × Height
What are the units for mass, gravitational field strength, and height?
Mass: Kilograms (kg)
Gravitational field strength: Newtons per kilogram (N/kg)
Height: Meters (m)
What is power in physics?
Power is the rate at which work is done or energy is transferred. It is measured in watts (W).
What is the equation for power?
Power = Work done / Time taken
How can power be calculated using force and speed?
Power = Force × Speed
What is efficiency?
Efficiency is a measure of how much useful energy is converted from the total energy input. It is expressed as a percentage.
What is the equation for efficiency?
Efficiency = (Useful energy output / Total energy input) × 100%
What is meant by energy dissipation?
Energy dissipation refers to the spreading out of energy into less useful forms, often as heat, which reduces the efficiency of energy transfer.
What is elastic potential energy?
Elastic potential energy is the energy stored in an elastic object, like a spring, when it is stretched or compressed.
What is Hooke’s Law?
Hooke’s Law states that the extension of an elastic object is directly proportional to the force applied, up to the limit of proportionality.
What is the equation for Hooke’s Law?
Force = Spring constant × Extension
What are the units for the spring constant and extension?
Spring constant: Newtons per meter (N/m)
Extension: Meters (m)
What happens when a material reaches its elastic limit?
When a material reaches its elastic limit, it no longer returns to its original shape, and permanent deformation occurs.
What factors affect the amount of work done to overcome friction?
The amount of work done to overcome friction depends on the size of the frictional force and the distance over which the force acts.
