gamma radiation and heat flares from the sun, they use refelective gold sheets
Physical changes are those which do not affect the chemical properties of a substance. For example, when a paper is cut, the two pieces obtained are still paper. The chemical properties have not changed. Only, physically when one piece is cut to two. A chemical change occurs when the chemical properties change and a new substance with different chemical properties is obtained. For example, when the paper is burnt, it turns to ashes. Hence, this is a chemical change.
When a substance undergoes a physical change, the physical properties of the substance changes like the state (solid to liquid during melting), shape, size, volume etc. Many physical changes are reversible whereas, in general many chemical changes are irreversible.
Answer:
2.72×10^-7
Explanation:
velocity = frequency × wavelength
2.05×10^8=7.55×10^14 wavelength
wavelength = 2.05×10^8/7.55×10^14
wavelength = 2.72×10^-7
Answer: P= W/t so P=50/20 =2.5 W
Answer:
Newton's third law of motion.
Explanation:
We are told the force needed to throw the full soda can was more than that needed to throw the empty can.
Now, the weight of the full soda can will be more than that of the empty can. Therefore, the full can will demand more force than that of the empty can due to Newton's third law of motion which states that to every action, there is an equal and opposite reaction.
