1. Millions of gallons of water are wasted by households in America on a yearly basis as a result of wastage of water in the laundry rooms. There are many ways by which water can be conserved in the laundry room, these include:
1. Using a high efficiency washing machine.
2. Choosing the right load sizes and cycles when using washing machines.
3. Wearing clothes more than once before washing them.
4. Collection of grey and rain water.
5. Treat difficult stains before washing them.
2. Using a high efficiency machine will ensure that water is used efficiently. A high efficiency washing machine uses much less water and save about 6,000 gallons of water for an average family on a yearly basis according to Environmental Protection Agency.
Grey water refers to water that have used once. Water that has been used for washing clothes or bathing can be collected again, recycle and use for some household needs such as gardening, flushing of toilet, etc. Water tanks can also be installed to collect rain water which can be used for washing clothes. This will have positive effect on household overall water consumption.
Wouldn't it be neat if an electron falling closer to the nucleus ... emitting a
photon ... actually gave out more energy than it needed to climb to its original
energy level by absorbing a photon ! If there were some miraculous substance
that could do that, we'd have it made.
All we'd need is a pile of it in our basement, with a bright light bulb over the pile,
connected to a tiny hand-crank generator.
Whenever we wanted some energy, like for cooking or heating the house, we'd
switch the light bulb on, point it towards the pile, and give the little generator a
little shove. It wouldn't take much to git 'er going.
The atoms in the pile would absorb some photons, raising their electrons to higher
energy levels. Then the electrons would fall back down to lower energy levels,
releasing more energy than they needed to climb up. We could take that energy,
use some of it to keep the light bulb shining on the pile, and use the extra to heat
the house or run the dishwasher.
The energy an electron absorbs when it climbs to a higher energy level (forming
the atom's absorption spectrum) is precisely identical to the energy it emits when
it falls back to its original level (creating the atom's emission spectrum).
Energy that wasn't either there in the atom to begin with or else pumped
into it from somewhere can't be created there.
You get what you pay for, or, as my grandfather used to say, "For nothing
you get nothing."
Answer:
1. 75N
2. 67,983 J (=67.98 kJ)
Explanation:
1. Work = Force x Distance
we are given that Work = 1,500J and Distance = 20m
hence,
Work = Force x Distance
1,500 = Force x 20
Force = 1,500 ÷ 20 = 75N
2. Potential Energy, PE = mass x gravity x change in height
we are given that mass = 165 kg and change in height = 42m
assuming that gravity, g = 9.81 m/s²
Potential Energy, PE = mass x gravity x change in height
Potential Energy, PE = 165 x 9.81 x 42 = 67,983 J (=67.98 kJ)
