A radio telescope is simply a telescope that is designed to receive radio waves from space. In its simplest form it has three components:
1. One or more antennas to collect the incoming radio waves. Most antennas are parabolic dishes that reflect the radio waves to a receiver, in the same way as a curved mirror can focus visible light to a point.
2. A receiver and amplifier to boost the very weak radio signal to a measurable level. These days the amplifiers are extremely sensitive and are normally cooled to very low temperatures to minimise interference due to the noise generated by the movement of the atoms in the metal (called thermal noise).
3. A recorder to keep a record of the signal. Most radio telescopes nowadays record directly to some form of computer memory disk as astronomers use sophisticated software to process and analyse the data.
When at the bottom of the dip, the only force that keeps the car in the circular trajectory, is the centripetal force.
This force is not a new force, is just the net force aiming to the center of the circle.
In this case, is just the difference between the normal force (always perpendicular to the surface, pointing upward) and the force that gravity exerts on the car (which is known as the weight), pointing downward.
So, we can write the following expression:
It can be showed that the centripetal force is related to the speed by the following expression:
The normal force, it is called the apparent weight, because it would be the weight as measured by a scale.
Replacing (2) in (1), and solving for Fn, we get:
Now, we need to find the value of v that makes Fn, exactly 15% more than the weight m*g, so we can write the following equation:
Replacing Fg by its value, simplifying, and solving for v, we get:
The best way to deterime which cloth with absorb heat is to put each cloth outside in the heat with a thermometer under it and see which has the highest tempe.
