Answer:
kinetic energy=1/2mv^2.
which is 4320000=1/2×m×23^2.
which is 4320000=1/2×m×529.
4320000=264.5m.
m=4320000/264.5.
m=16332.70~16333g
Answer:
a) B = 1.99 x 10⁻⁴ Tesla
b) B = 0.88 x 10⁻⁴ Tesla
Explanation:
According to Biot - Savart Law, the magnetic field due to a currnt carrying straight wire is given as:
B = μ₀ I L/4πr²
where,
μ₀ = permebility of free space = 1.25 x 10⁻⁶ H m⁻¹
I = current = 2 A
L = Length of wire = 40 cm = 0.4 m
a)
r = radius of magnetic field = 2 cm = 0.02 m
Therefore,
B = (1.25 x 10⁻⁶ H m⁻¹)(2 A)(0.4 m)/4π(0.02 m)²
<u>B = 1.99 x 10⁻⁴ Tesla</u>
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b)
r = radius of magnetic field = 3 cm = 0.03 m
Therefore,
B = (1.25 x 10⁻⁶ H m⁻¹)(2 A)(0.4 m)/4π(0.03 m)²
<u>B = 0.88 x 10⁻⁴ Tesla</u>
Answer:
Explanation:
The energy of a photon is given by the equation 
, where h is the <em>Planck constant</em> and f the frequency of the photon. Thus, N photons of frequency f will give an energy of 
.
We also know that frequency and wavelength are related by 
, so we have 
, where c is the <em>speed of light</em>.
We will want the number of photons, so we can write
We need to know then how much energy do we have to calculate N. The equation of power is 
, so for the power we have and considering 1 second we can calculate the total energy, and then only consider the 4% of it which will produce light, or better said, the N photons, which means it will be 
.
Putting this paragraph in equations:
.
And then we can substitute everything in our equation for number of photons, in S.I. and getting the values of constants from tables:
I think, I do think.. that it is D.
Wouldn't it be simple to divide 5 from 20, that would equal 4.
4 earthworms per square meter.
Answer. Explanation: Frequency of the sound decreases and the speed of sound becomes 346m/s from near about 1500 m/s.
