physics

• A vector quantity has both magnitude and direction, while a scalar quantity only has magnitude.
• force= spring constant x extension
• density = mass/volume
• distance = speed x time
• acceleration= (final velocity- initial velocity)/time
• weight= mass x gravitational field strength
• resultant force = mass x acceleration
• momentum = mass x velocity
• efficiency = useful energy out / total energy in
• kinetic energy = 0.5 x mass x speed squared
• gravitational potential energy= mass x height x gravitational field strength (10)
• lubrication applying oil fro less friction
• non renewable resources are finite
• advatages of fossile fuels are reilable, cheap, release large amounts of energy
• wind, sloar , water waves are renewable- they wont run out
• geothermal power is used near volcanoes where hot rock is close to the surface
• there is a problem with wind power if there is no or too much wind
• bio-fuels are made from plants and waste
• kinetic energy= energy every moving object has
• food,fuel,batteries are examples of chemical energy
• wind, solar , hydroelectricity, tidal are all examples of renewable energy souces
• hydroelectricity is energy used from dams (water)
• tidal energy is the movement of tides which can be harnessed to generate electricity
• when something falls energy from its gravitational potential energy store is transferred to its kenetic energy store
• stretching or squashing an object can transfer energy its elastic potential energy
• lifting an object creates gravitational potential energg
• specific latent heat is the amount of energy needed to change the state of 1 kg of the substance