Half-life of a radioactive substance is the time required to reduce the amount of substance to half of its initial amount.
In present case, half-life is material is given as 1000 years and initial amount of material is given as 400 kg
Answer 1) Since, half-life of radio-active substance is 1000 years, therefore after 1st half life, amount of the material will be left to half the initial amount. Hence, amount of substance left after 1000 years = 400/2 = 200 kg.
Answer 2) For 2000 years, radioactive material has crossed 2 times the half life. Therefore , amount of the material will be left to 1/4 the initial amount. Hence, amount of substance left after 2000 years = 400/4 = 100 kg.
Answer 3) For 4000 years, radioactive material has crossed 4 times the half life. Therefore , amount of the material will be left to 1/16 the initial amount. Hence, amount of substance left after 4000 years = 400/16 = 25 kg.
Answer:
The average kinetic energy of a particle is proportional to the temperature in Kelvin.
Explanation:
The kinetic molecular theory states that particles of matter are in constant motion and collide frequently with each other as well as with the walls of the container.
The collisions between particles are completely elastic. The kinetic energy of the particles of a body depends on the temperature of the body since temperature is defined as a measure of the average kinetic energy of the particles of a body.
Therefore, the average kinetic energy of a particle is proportional to the temperature in Kelvin.
the law of thermodyanamic is the restatement of the law of conservation of energy
Answer:flashover
Explanation: flashover are event that occurs when all of the combustible materials in a room reach their ignition temperatures at the same time
