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.
Answer:
The correct option is A
Explanation:
From the question we are told that
The mass number is 
Generally the mean radius is mathematically evaluated as

Here
is a constant with a value 
So



When the dust is too thick to penetrate with visible light, such as the Nebula, Radio Waves are used to penetrate the dust. Longer radio waves can completely penetrate the thick cloud cover, allowing scientists to beam radar waves.
The first thing you should know for this case is that density is defined as the quotient between mass and volume:
D = M / V
In addition, you should keep in mind the following conversion:
1Kg = 1000g
Substituting the values we have:
D = (23.0 * 1000) / (2920) = 7.88 g / cm ^ 3
answer
the density of the iron plate is 7.88 g / cm ^ 3
Electrostatic repulsion is the force between two charges having the same sign, that tends to separate them further. The force is proportional to the product of the charges, and inversely proportional to the square of the distance between them.