Answer:
Explanation:
Given
Wavelength of radiation 
We know Energy of wave with wavelength
is given by

where h=Planck's constant
c=velocity of light
=wavelength of wave

Hence the energy of the wave with wavelength 784 m is
Answer:
44.1 m
Explanation:
<u>Given:</u>
= speed of sound in air = 343 m/s
= speed of sound in the rod = 
= times interval between the hearing the sound twice = 0.12 s
<u>Assumptions:</u>
= length of the rod
= time taken by the sound to travel through the rod
= time taken by the sound to travel to through air to the same point = 
We know that the distance traveled by the sound in a particular medium is equal to the product of the speed of sound in that medium and the time taken.
For traveling sound through the rod, we have
..........eqn(1)
For traveling sound through the air to the women ear for traveling the same distance, we have

Hence, the length of the rod is 44.1 m.
False. First Law of Newton states that object tends to be at rest until an external force is applied and vice-versa.
"watt" means "Joule of energy per second"
"60 watts" means "60 Joules per second"
(60 joules per second) x (5 seconds) = <em>300 Joules of energy</em>