Physics Quiz 3

From this, we can estimate the radius of the earth as the point of the horizon must cover the circumference of the Earth.

The atmospheric air is held to the Earth by gravity. Earth's gravity is strong enough to hold onto its atmosphere and keep it from drifting into space.

A communications satellite's transponder is the series of interconnected units that form a communications channel between the receiving and the transmitting antennas. It is mainly used in communication satellite to receives signals from an earth station and transmits them to different directions.

Anemometer is an instrument used to measure the force, pressure and velocity (speed) of the wind. It is an important tool for meteorologists, who study weather patterns.

For a body moving with non-uniform velocity and uniform acceleration, Displacement–Time graph is nonlinear. Non-uniform motion occurs when an object's velocity (either the magnitude, or the direction, or both) is variable (i.e. the object undergoes acceleration).

The shape of our milky way galaxy is spiral. The Milky Way is a huge collection of stars, dust and gas. It's called a spiral galaxy because if you could view it from the top or bottom, it would look like a spinning pin-wheel.

Shock-absorbers are usually made of steel as it has higher elasticity. They are used in vehicles so that the time interval of the jerk increases. Hence, the rate of momentum decreases. Therefore, during the jerk, a lesser force is exerted on the passengers.

A battery is a DC voltage source that converts chemical energy to electrical energy. The chemical reactions in a battery involve the flow of electrons from one material (electrode) to another, through an external circuit.

When warm air (over the fire spot) rises, the air pressure at that place gets lowered. But around it, pressure is high so the air rushes from high-pressure zone to low-pressure zone giving an appearance of fanning the fire.

Milk is put in a container in a centrifuge machine and the container is spun at a very high speed. The centrifugal forces act on milk and separate the milk into a cream that is lighter thus floats on top and skimmed milk which is at the bottom. Then cream can be separated from the milk.