What happens to wasted energy??Isn't it not 'lost'.A crane lifts an iron girder which has a mass of 300kg through a height of 10m.a) What is the wieght of the girder??B) What is the gain in potential energy of the girder??C)The motor of the crane is 50% efficient, how much energy does the motor transfer to the lift the girder???Thank you!!!!!!.
you cant stop dust to enter your house so better clean your indoor regularly.
What kind of vacuum cleaner do you have? Many old or cheap cleaners end up putting tons of dust into the air while you vacuum, which can then settle over the next few hours and build up over time.
Oh dust, so small but so persistent! The filter sounds like a great ideaAlso, you might want to consider the type of vacuum you use for your hardwood floorsIt could just be blowing the dust around the room as you cleanMake sure it has a good filter and that the filter is kept cleanConsider these steps: 1Do a round with the vacuum on floors and all possible surfaces with an attachment, 2Then dust and clean surfaces that the vacuum can't tackle 3Follow with a quick, final pass with the vacuum on your floorsAn extra quick step but it might help to get rid of all the dust that lingers after cleaning surfaces above the floorDust be gone!
Gravity 10m/s^2 a) the weight mg30010 3000N b) potential energy Fd 300010 30kJ c) efficiency work output/work input 100 50 30000/ work input 100 50 work input 30000 100 work input 30000 100 / 50 60000J 60KJ
