Answer:
Explanation:
We have a metal ring of diameter
d = 4.2cm = 0.042m
r = d/2 = 0.021m
And it is place between the north pole and south pole of a large magnet with the plane of it's area perpendicular to the magnetic field.
Given that the magnetic field is
B = 1.12 T
The rate of decrease of magnetic field is 0.2T/s, since it is decrease then,
dB/dt = -0.2 T/s
The induce electric field is given as,
From faradays law
ε = ∫E•dl = -dΦ/dt
Magnetic flux is given as
Φ = BA
Φ = πr²×B = πr²B
Also, ∫E•dl = E×2πr = 2πrE
So,
∫E•dl = -dΦ/dt
2πrE = -d(πr²B) / dt
r is a constant, then
2πrE = -πr² dB/dt
Divide both side by πr
2E = -r dB/dt
E = -r dB/dt / 2
E = -0.021 × -0.2 / 2
E = 0.0021 V/m
The magnetic field point from north to south pole and it is decreasing and this means that the magnetic flux is also decreasing, so the induce magnetic field must point in the same direction of the original magnetic field, so the induce current circulate counter-clockwise as viewed from the south pole
D = (1/2)·at²
where d is the distance fallen, a is the acceleration (g in this problem), and t is the time
d = (1/2)·(9.8 m/s²)·(30 s)² = (1/2)·(9.8)·(900) m
d = 4410 m
The answer is b) 4410 m
Note: the mass of the raindrop is irrelevant since the acceleration due to gravity is independent of mass. (Galileo's Leaning Tower of Pisa experiment)
Medium stars become dwarf stars, large stars become either neutron (pulsar) stars or black holes
A. The particles are packed more tightly in materials with more density which causes the vibrations to bounce of the partials more rapidly which makes them go faster
The reason for people to swim easier in salt water than fresh water is because of buoyancy
Explanation:
In fresh water there is lack of minerals and has fresh water alone. The density of fresh water is 1000 kg/m³. Hence, in fresh water cannot exert the suitable buoyancy for the swimmer to float easier than that of salt water.
But in Salt water due to enrichment of salts and minerals it is found that salt water has more density than fresh water. Here the salt water offers more buoyancy to the swimmer to lift him up in the water surface and to swim faster and easier than fresh water.
It is similar to that egg floats in the salt water and sinks inside the fresh water because of its own body weight.
