Answer:
Energy is found as:
E = 1.987·10⁻¹⁹ J
Explanation:
Energy of a single photon of infrared light can be found by using the following formula:

where
E = in Joules
h = Planck's constant = 6.627×10 ⁻³⁴ J
f = frequency in hertz
It can also be written as:

where
c = 2.998×10⁸ ms⁻¹
λ = wavelength
Wavelength is given in the question which is:
λ = 1×10⁻⁶m
Substitute all the values in the Energy formula

work done = force * distance
work = 62 * 2 = 124 j
It is a chemical change because the salt is dissolving.
Answer:
20 Hz, 20000 Hz
0.0166 m, 16.6 m
Explanation:
The minimum frequency that a human ear can hear is 20 Hz
The maximum frequency that a human ear can hear is 20000 Hz.
v = Velocity of sound = 332 m/s
Wavelength is given by

The longest wavelength that can be heard by the human ear is 16.6 m

The shortest wavelength that can be heard by the human ear is 0.0166 m.