Answer:
340.67 kgm²/s
Explanation:
R = Radius of merry-go-round = 1.9 m
I = Moment of inertia = 209 kgm²
= Initial angular velocity = 1.63 rad/s
m = Mass of person = 73 kg
v = Velocity = 4.8 m/s
Initial angular momentum is given by
![L=I\omega_i\\\Rightarrow L=209\times 1.63\\\Rightarrow L=340.67\ kgm^2/s](https://tex.z-dn.net/?f=L%3DI%5Comega_i%5C%5C%5CRightarrow%20L%3D209%5Ctimes%201.63%5C%5C%5CRightarrow%20L%3D340.67%5C%20kgm%5E2%2Fs)
The initial angular momentum of the merry-go-round is 340.67 kgm²/s
Answer:
hypernova making a black hole, and merger of two neutron stars
Explanation:
It is given that,
Length of wire, l = 0.53 m
Current, I = 0.2 A
(1.) Approximate formula:
We need to find the magnitude of the magnetic field made by the current at a location 2.0 cm from the wire, r = 2 cm = 0.02 m
The formula for magnetic field at some distance from the wire is given by :
![B=\dfrac{\mu_oI}{2\pi r}](https://tex.z-dn.net/?f=B%3D%5Cdfrac%7B%5Cmu_oI%7D%7B2%5Cpi%20r%7D)
![B=\dfrac{4\pi \times 10^{-7}\times 0.2\ A}{2\pi \times 0.02\ m}](https://tex.z-dn.net/?f=B%3D%5Cdfrac%7B4%5Cpi%20%5Ctimes%2010%5E%7B-7%7D%5Ctimes%200.2%5C%20A%7D%7B2%5Cpi%20%5Ctimes%200.02%5C%20m%7D)
B = 0.000002 T
![B=10^{-5}\ T](https://tex.z-dn.net/?f=B%3D10%5E%7B-5%7D%5C%20T)
(2) Exact formula:
![B=\dfrac{\mu_oI}{2\pi r}\dfrac{l}{\sqrt{l^2+4r^2} }](https://tex.z-dn.net/?f=B%3D%5Cdfrac%7B%5Cmu_oI%7D%7B2%5Cpi%20r%7D%5Cdfrac%7Bl%7D%7B%5Csqrt%7Bl%5E2%2B4r%5E2%7D%20%7D)
![B=\dfrac{\mu_o\times 0.2\ A}{2\pi \times 0.02\ m}\times \dfrac{0.53\ m}{\sqrt{(0.53\ m)^2+4(0.02\ m)^2} }](https://tex.z-dn.net/?f=B%3D%5Cdfrac%7B%5Cmu_o%5Ctimes%200.2%5C%20A%7D%7B2%5Cpi%20%5Ctimes%200.02%5C%20m%7D%5Ctimes%20%5Cdfrac%7B0.53%5C%20m%7D%7B%5Csqrt%7B%280.53%5C%20m%29%5E2%2B4%280.02%5C%20m%29%5E2%7D%20%7D)
B = 0.00000199 T
or
B = 0.000002 T
Hence, this is the required solution.
A I think it was sorry if not
Frictional forces act in the direction opposite to the MOTION. That direction could be the same OR opposite to applied force.
-- If you push a loaded heavy wagon from behind, trying to get it going faster, friction is acting against you, opposite to your force.
-- If you push a loaded rolling heavy wagon from in front, trying to make it slow down, friction is acting with you, in the same direction as your force.
-- Opposite to the motion both times.