Answer: The poker stick should have low thermal conductivity and high specific heat.
Explanation: For a poker stick that is non flammable, it should have some properties which will not let it heat up faster.
Two properties that satisfy the poker stick are:
- Specific heat
- Thermal conductivity
Specific heat is defined as the amount of heat require to raise the temperature of a mass M by 1 °C. More the specific heat, more amount of heat will be required to raise the temperature of a substance.
Thermal conductivity is defined as the ability of a substance to conduct heat. More thermal conductivity means that the substance will get hot faster as it will conduct more amount of heat.
So, for a substance that should not conduct more heat like the poker stick must have high specific heat and low thermal conductivity.
By studying meteorites which are the most ancient material in space.
Treatment water from the plant would affects the communities present in the downstream of the river.
Answer: Option (a)
<u>Explanation:</u>
Wastewater treatment plant is a process used to treat the water that flows from the rivers, streams, and lakes.This plant removes the dust, sand, sediments present in the river water.
When this treated water is released into the downriver stream, it affects the health of aquatic organisms present in that stream.Use of chemicals in treating the wastewater may cause genetic problems to the communities present in that region.
It also causes air pollution and more energy is needed for the treatment process and thus affects the ecosystem.
Doppler Effect is required to solve the problem. The Doppler effect is the change in the perceived frequency of any wave movement when the emitter, or focus of waves, and the receiver, or observer, move relative to each other. The general formula of observed frequency, due to Doppler's effect is as follows,

= Frequency observed by observer
v = Velocity of Sound
= Velocity of observer
= Velocity of source
= Frequency of source
PART A) Replacing our values we have that,



PART B) Here the same procedure is performed but this time repeated in the opposite direction.


