Answer:
=24.25 ^−1
Explanation:
Let and be initial and final velocity of the body respectively,
be acceleration due to gravity ( 9.8^−2 ), ℎ be the height of the body.
=0 ^ −1
ℎ=30
we know that, ^2−^ 2=2ℎ
^2=2∗9.8∗30
^2=588
=24.25 ^−1
Answer:
240 V
Explanation:
number of turns in primary coil, Np = 10
Number of loops in secondary coil, Ns = 20
Voltage in primary coil, Vp = 120 V
Let the voltage in secondary coil is Vs.
So, Vs / Vp = Ns / Np
Vs / 120 = 20 / 10
Vs / 120 = 2
Vs = 240 V
Thus, the voltage in secondary coil is 240 Volt.
1/2mv^2
1/2x12x10^2=600J
The kinetic energy is 600J
Answer:
The right approach is Option b (the force..................exert on you).
Explanation:
- Even before you fall on something like a soft object, users eventually slow to a halt. You are still giving away all the downward momentum, but progressively although with small powers, you are doing so.
- Although you can get injured by massive powers, this gradual displacement is a positive thing. And that is why you have a mattress you would like to settle on.
The other options given are not connected to the situation described. So, the solution here was the right one.
Answer:
7.78x10^-8T
Explanation:
The Pointing Vector S is
S = (1/μ0) E × B
at any instant, where S, E, and B are vectors. Since E and B are always perpendicular in an EM wave,
S = (1/μ0) E B
where S, E and B are magnitudes. The average value of the Pointing Vector is
<S> = [1/(2 μ0)] E0 B0
where E0 and B0 are amplitudes. (This can be derived by finding the rms value of a sinusoidal wave over an integer number of wavelengths.)
Also at any instant,
E = c B
where E and B are magnitudes, so it must also be true at the instant of peak values
E0 = c B0
Substituting for E0,
<S> = [1/(2 μ0)] (c B0) B0 = [c/(2 μ0)] (B0)²
Solve for B0.
Bo = √ (0.724x2x4πx10^-7/ 3 x10^8)
= 7.79 x10 ^-8 T
