Kinetic and Potential Energy Stores Flashcards
If anything is moving, what energy store is the energy in?
Kinetic
What is the equation for kinetic energy?
Kinetic energy =
0.5 x Mass x (Speed)²
What is the symbol equation for kinetic energy?
Ek = 0.5 m x (v)²
J) (Kg) (m/s
When is energy transferred to an object’s kinetic energy store?
Energy is transferred to when an object speeds up, and away when an object slows down
What factors affect the energy in an objects kinetic energy store?
The object’s mass and speed. The greater the mass and speed, the more kinetic energy
What is the equation for gravitational potential energy?
GPE =
Mass x Gravitational Field Strength x Height
What is the symbol equation for gravitational potential energy?
Ep = m x g x h
J) (Kg) (m/s²) (m
What is the gravitational field strength on earth?
9.8N/Kg
When is an object’s energy transferred to the gravitational potential energy store?
When an object is lifted, as it requires work
What factors affect the amount of energy in a gravitational potential energy store?
The object’s mass, height, and strength of the gravitational field an object is in (9.8)
When an object falls, what is its gravitational potential energy transferred into?
Kinetic energy
What is the equation for elastic potential energy?
Elastic Potential =
0.5 x Spring Constant x (Extension)²
What is the symbol equation for elastic potential?
F = 0.5 x k x (e)²
J) (N/m) (m
What transfers an energy to an object’s elastic potential store?
Stretching/Squashing an object
What is Hooke’s law?
The strain in a solid is proportional to the applied stress within the elastic limit of that solid
What is the limit of proportionality?
- The point where Hooke’s law no longer exists
- The stretched material will no longer return to its original length when force is removed
EXAMPLE 1
What happens when you throw a ball upwards?
- Initial force is exerted by a person
- Work is done
- Energy is transferred from the chemical store (ARM) to the kinetic store (ARM and BALL)
EXAMPLE 2
What happens when a ball is dropped?
- Gravity does the work
- Energy is transferred from the gravitational store (BALL) to the kinetic store (BALL)
EXAMPLE 3
What happens when a car brakes?
- Friction does the work
- As it slows down, energy transfers from the kinetic store (WHEEL) to the thermal store (SURROUNDINGS)
