Vacum flask has inner layer of glass and outer body of plastic.the glass has a reflective metal layer..when a hot drink is poured into the flask it prevents conduction.tight lid stops the convection.when radiation tries to leave the hot drink the reflective layer of the glass reflects it back so no heat can escape.
Answer:
If one end of a metal bar is heated, the atoms at that end vibrate more than the atoms at the cold end. The vibration spreads along the bar from atom to atom.
Explanation:
The spread of heat in this way is called conduction. Metals are good conductors of heat.
Answer: Electromagnetic waves (Ultraviolet light, between 100 nm and 380 nm)
Explanation:
Solar cells work by the photoelectric effect, which consists of the emission of electrons (electric current) when light (electromagnetic waves) falls on a metal surface under certain conditions.
In this sense, the portion of the electromagnetic spectrum this cells use is Ultraviolet light (UV) from the Sun, whose wavelength is approximately between 100 nm and 380 nm.
It is important to note, this is a type of electromagnetic radiation that is not visible to the human eye.
Answer: 44m/s
Explanation:
Speed of Car A travelling left = 22m/s
Speed of Car B travelling right = 22m/s
Now recall that relative speed of objects moving in opposite directions is equal to the sum of each speed
Hence, Relative speed = (Speed of Car A + Speed of Car B)
= (22m/s + 22m/s)
= 44m/s
The purpose of a rear view mirror in a car is to see behind the car, if there is any car coning or not.
