Physics Questions

As water is cooled from 4 deg C to 0 deg C, the water reaches its freezing point and starts forming ice crystals. Then the volume of that ice cubes increases and its density decreases. Hence, it is the reason that ice will float on water as ice has less density than the water.

The land breeze is a coastal breeze at night blowing from the land to the ocean. It is caused by the difference in the rates of cooling of the land and of the ocean. Once again, the bigger the difference in temperature between the two, the stronger the wind.

The easiest way would measure it through half a liter water bottle. There are approximately 16.9 ounces(oz) of water in a 500ml water bottle.

Gallon is an imperial customary volume unit for the U.S.

As we have previously mentioned, the 16.9oz bottle is also known as 500ml in the metric system. According to U.S. standard, 1 gallon stands for 128 fluid oz.

Hence, Number of bottles in 1 gallon = 128/16.9 = 7.57 =~ 8.

So, resistance of Wire 2 is R/4 as radius is half of wire 1, so area would be 4 times of wire 1.

Now for resistance in series. R= R1 + R2.

Therefore, Final R= R + R/4 = 5R/4

Sound intensity or level is measured by a unit called a decibel. An 85 decibel noise level is not a safe standard for the public.

Hence, Acceptable noise level for human ear is less than 85 db.

Electrostatic precipitator is used to control Air pollution. An electrostatic precipitator is a filtration device that removes fine particles, like dust and smoke, from a flowing gas using the force of an induced electrostatic charge minimally impeding the flow of gases through the unit.

Bicycle is a compound machine in the above given options. A compound machine is a machine that is formed by two or more simple machines.