Mechanics, Work and Energy Flashcards
What is Work done?
When a force moves an object and energy is transferred.
How do we calculate Work done?
Work done = Force x distance, Work = Fd
What energy is transferred if a force of 2N moves a distance of 10m?
Work = Fd Work = 2N x 10m = 20J
If Work lifts an object against gravity what energy is gained?
Potential Gravitational Energy EP
What do the letters of this formula, EP = mgh
Gravitational Potential energy = mass x acceleration against gravity (10ms-2) x height
Calculate the change in EP when a person lifts 5kgs from the floor to a shelve 2m high.
Ep = mgh Ep = 5 x 10 x 2 = 100J
What is Kinetic Energy?
The energy of a moving object EK
If an object is lifted higher what energy increases?
Gravitational Potential Energy (EP)
How does energy move through a system?
Energy is transferred from object to object
What is happening to energy as an object falls?
EP, Potential Gravitational Energy is transferred to EK, Kinetic Energy
What energy is formed when the Kinetic energy of a moving car has the brakes applied?
EK to Heat in the brakes and tyres
What energies are formed when the Kinetic energy of a Wind turbine is transferred?
Electrical, heat and sound.
What energy is formed when a Roller coaster wagon is pulled up a ramp?
Gravitational Potential, heat and sound
The amount of kinetic energy of an object relates to which to factors?
Mass (m) and speed (v)
What is the calculation for EK, Kinetic Energy?
EK = ½mv2