Energy stores
As an object falls, which energy store decreases?
gravitational potential
from chemical store (of petrol) to kinetic store (of car)
What units do we use to measure pressure?
Pa or N/m^2
What is the gravitational field strength near the surface of Earth?
9.8 N/kg
What happens to the elastic potential energy of a spring when it is stretched further?
Increases
The amount of energy in an object's kinetic store depends on two things: its speed and what else?
its mass
An incandescent light bulb wastes a lot of energy. How is that wasted energy transferred to the surroundings?
as heat
Energy is measured in what units?
joules (J)
friction
What is the formula for calculating pressure?
F/A
Energy stored in the bonds between atoms is said to be in which energy store?
chemical store
When a moving object slows down due to friction, which energy transfer takes place?
Kinetic energy to thermal energy.
What units do we use to measure weight?
newtons (N)
Which energy resource is non-renewable: hydroelectric, biofuel, nuclear, geothermal?
nuclear
When a compressed spring is released, what type of energy transfer occurs?
Elastic potential energy to kinetic energy.
An inflated balloon has a lot of energy in which store?
elastic potential
What type of energy transfer happens when a rock falls to the ground?
Gravitational potential energy to kinetic energy.
What units do we use to measure a spring constant?
newtons per metre (N/m)
Which law states that the extension of a spring is proportional to the applied force, as long as the spring is not stretched beyond its elastic limit?
Hooke's law
Why does a sharp knife cut better than a dull one?
sharp knife has a smaller area, increasing the pressure for the same force.
When a stretched spring is released, energy from its elastic potential store is ultimately transferred into which store?
kinetic store
When energy dissipates, it usually ends up in which energy store?
thermal store of surroundings
What is the unit of gravitational acceleration
m/s^2
If a force of 100 N is applied to an area of 2 m², what is the pressure?
50 N/m^2
If a spring is stretched 5 cm under a force of 10 N, what is its spring constant?
200 N/m