Work and Power9 Flashcards
How do you calculate work done?
Work done = force x distance
(J). (N). (m).
Or
Work done = weight x height
(J). (N). (m)
How do you calculate gravitational potential energy(GPE)?
GPE = mass x gravitational field strength x height
(J). (kg). (N/kg). (m)
*gravitational field strength always equals 10
Or
GPE = weight x height
(J). (N). (m)
How do you calculate kinetic energy?
Kinetic energy = 0.5 x mass x speed^2
How do you calculate power?
Work done(energy transferred) (J)
Power (W) = ---------------------------------
Time taken (s)What is work done equal to?
Energy transferred
What is the relationship between work, GPE and kinetic energy?
Work done lifting object = gain in GPE = gain in kinetic energy just before hitting the ground
What is power a measure of?
Power is a measure of how fast energy is transferred of transformed.
When something falls over why does it lose GPE when it falls?
- height above ground is smaller
- GPE=weight❎height ,therefore if the height is smaller then the GPE is smaller
When does the motion of an object change?
When an unbalanced force acts on it
What do you do when given kg when you need newtons?
Do kg x 10
