Physics Quiz 4

When the pendulum is taken to the moon, the value of 'g' will decrease and hence time period will increase.

Alnico is a family of iron alloys which in addition to iron are composed primarily of aluminium (Al), nickel (Ni), and cobalt (Co), hence the acronym al-ni-co. They also include copper, and sometimes titanium. Alnico alloys are ferromagnetic, and are used to make permanent magnets.

The spoon dropped by an astronaut in a satellite will continue to follow the motion of the satellite. The reason that an object (spoon) will maintain its orbit, regardless of its position in the orbit, is because the gravitational force from the larger object (earth) will constantly act upon the smaller object, thereby pulling the smaller object towards the larger object.

An anemometer is an instrument that measures wind speed and wind pressure. Anemometers are important tools for meteorologists, who study weather patterns.

The principle involved in a refrigerator is the rapid absorption of heat by the rapid evaporation of a volatile liquid. Refrigerators use a liquid that evaporates very easily, and this evaporation creates a cooling effect. They then compress the gas into a liquid again, and the whole process starts over.

When the medium is dense, the molecules in the medium are closely packed, which means that the sound travels faster. Therefore, the speed of sound increases as the density of the medium increases.

The egg is denser than the soft water, this causes it to sink. Dissolving salt in the water increases the density (adding more molecules per square inch).

A nonrenewable resource is a natural substance that is not replenished with the speed at which it is consumed. There are four major types of nonrenewable resources: oil, natural gas, coal, and nuclear energy. Oil, natural gas, and coal are collectively called fossil fuels.

A geostationary satellite is an earth-orbiting satellite, placed at an altitude of approximately 35,800 km directly over the equator, that revolves in the same direction the earth rotates (west to east). At this altitude, one orbit takes 24 hours, the same length of time as the earth requires to rotate once on its axis. So they seem stationary, relative to the Earth's surface.

One of the most common examples of Pascal's Law is the hydraulic braking system present in automobiles. According to this law when pressure is applied on fluid it travels equally in all directions so that uniform braking action is applied on all four wheels.