Answer:6.298,4.1,1.9015
Explanation:
Wavelength=
=
=4.397 m
Distance of 3rd speaker from speaker A is x
From B 78-x
Difference between the distances must be a whole number of wavelengths
First
for 1 st wavelength
2x=8.2+4.397=12.597
x=6.298m
second
For zero wavelength

2x=8.2
x=4.1m
Third

x=1.9015 m
Answer:
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Explanation:
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True. No matter can be created nor destroyed in pretty much every aspect of life, especially chemical reactions.
Answer:
A. 231.77 J
B. 5330.71 J
C. 46 donuts
Explanation:
A. To lift the barbell once, she will have to extend it the full length of her arm. The work done will then be:
W = F * d
Where the force is the weight of the barbell.
F = m * g
Hence, the work done in lifting the barbell is:
W = m * g * d
W = 43 * 9.8 * 0.55
W = 231.77 J
B. If she does 23 repetitions, the total energy she expend will be equal to the Potential energy when the barbell is lifted multiplied by 23:
E = 23 * m * g * d
E = 23 * 231.77
E = 5330.71 J
C. 1 Joule = 4.184 calories
5330.71 Joules = 5330.71 * 4.184 = 22303.69
If 1 donut contains 490 calories, the number of donuts she will need will be:
N = 22303.69/490 = 45.5 donuts or 46 donuts