Answer:
Work = F * s where s is the distance F moves
Since F is stationary, in this case, "no work" is done by either person
Answer:
437 Joules
Explanation:
Use the formula for work directly
(work) = (force) x (displacement)
to get
(work) = (19 N) x (23 m) = 437 Joules
The relationship between the number of visible spectral lines are identical for atoms .However they have unique wavelengths.
Option B
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Explanation:</u>
A spectrum is a range of frequencies or a range of wavelengths. The photon energy of the emitted photon is equal to the difference between two states. For every atom there are quite many electron transitions and each has a energy difference.
This difference in wavelength causes spectrum .As each element emission spectrum is unique because each atom has different energy and causes uniqueness in the emission spectrum . Hence, due to the difference in energy it emits different wavelengths.
Answer:
wavelength = 4 m
Explanation:
For distance 6 and 8m and speed of sound in air = c.
The travel time form the various distances 6 and 8 are 6/c and 8/c respectively.
cos(wt1) + cos(wt2) = 0
for a shift in phase t1 = t - 6/c,
t2 = t - 8/c
substituting t1 and t2
cos(π - w(t - 8/c)) = cos(w(t - 6/c))
solving using trigonometry identities in radians.
we have,
π - 2πn = w(t - 8/c) - w(t - 6/c)
putting w = 2πf
π - 2πn = 2πf(t - 8/c) - 2πf(t - 6/c)
dividing both sides by π
1 - 2n = 2ft - 16(f/c) - 2ft + 12(f/c)
simplifying we have,
1 - 2n = -4(f/c)
solving for f we have,
f = c/4(2n - 1)
putting n=1 and c = 343m/s
f = (343/4)*(2(1) - 1)
f = 85.75 Hertz
wave lenght = c/f , where c= speed of sound in air , f= frequency
wave lenght = 343/85.75 = 4m