When paper burns, some of the chemical compounds in the
paper combine with oxygen in the air and become different
chemical compounds. That's a chemical change.
When iron rusts, or copper or silver turns green, that's the result
of the metal at the surface combining with the oxygen in the air and
forming a new chemical compound. Those are chemical changes.
When water evaporates, H₂O in the liquid phase gains thermal
energy and changes to H₂O in the gaseous phase. No chemical
compounds are lost, gained, or changed to other compounds.
It's just a physical change.
Answer: A, C and D
Explanation:
Interference occurs when two waves superimpose to form a wave having a smaller or larger amplitude.
Constructive interference is said to occur when two waves superimpose to produce a wave having larger amplitude. It occurs for the waves having phase difference of multiple of 2π. On the other hand, destructive interference occurs for the waves having phase difference π, 3π, ..and so on.
In the given picture, the bright regions represent constructive interference where as the dark ones between them represent destructive interference. Thus, the correct letters representing constructive interference are: A, C and D.
The answer should be D but if its not then im sorrry, idk
Answer:
ω' = 2.5 rad/s
Explanation:
mass of cockroach, m = 4 kg
mass of disk, M = 6 kg
Radius of disc= R
initial angular velocity, ω = 2 rad/s
Let the final angular velocity is ω'
As no external torque is applied, so the angular momentum is constant.
Angular momentum = Moment of inertia x angular velocity
I ω = I' ω'


ω' = 2.5 rad/s