4.1.1.2 Changes in Energy Flashcards
Work done:
the energy transferred when a force moves an object over a distance
How do you calculate work done?
W = Fs Work done(J) = Force(N) x distance moved in the direction of the force(m)
How do you calculate the kinetic energy of a moving object:
Calculating the kinetic energy of a moving object:
KE = ½ mv²
Kinetic energy (J) = ½ x mass(kg) x velocity (m/s)
How do you calculate the amount of gravitational potential energy gained by an object raised above ground level?
PE = mgh
Gravitational potential energy (J) = mass(kg) x gravitational field strength (N/kg) x change in height (m)
How do you calculate the amount of elastic potential energy stored in a stretch spring?
Elastic potential energy (E) = 0.5 x spring constant (N/m) x extension ² (m)
EE = ½ ke²
What is work done (elastic potential wise)?
When a spring is stretched or compressed
Work done =
elastic potential energy (as long as the elastic limit is not exceeded)
What is the kinetic energy of a moving body directly proportional to?
the square of its speed
What happens when there is an energy transfer of [elastic potential energy ——→ (mechanical pathway) gravitational potential energy] with an 100% efficient rate?
EE = EP