Answer:
Explanation:
Let the distance be d . When sound travels d and is reflected back , it is heard by person as echo . Time taken by sound to travel total of distance 2 d
= 2 d / v where v is velocity of sound.
When this time is .05 s at least , echo will be heard . velocity of sound in air 340 m /s
so for echo to be heard ,
2 d / 340 = .05
d = 340 x .05 / 2
= 8.5 m .
The boiling pot of water is completely open
First chose is meteor and the second one is asteroids
Radiation is the transfer of heat energy through space by electromagnetic radiation. Most of the electromagnetic radiation that comes to the earth from the sun is in the form of visible light. Light is made of waves of different frequencies.
The working equation for this one is:
E = F/Q, where E is the strength of the electric field, F is the electric force and Q is the charge. Substituting the corresponding values, the strength of the electric field is equal to
E = -30 nN/-3 nC
E = 10 nN/nC