The main advantage of an electromagnet over a permanent magnet is that the magnetic field can be quickly changed by controlling the amount of electric current in the winding. However, unlike a permanent magnet that needs no power, an electromagnet requires a continuous supply of current to maintain the magnetic field.
Answer:
<em>3924 Pa</em>
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Explanation:
Volume of cylinder = 2 L = 0.002 m^3 (1000 L = 1 m^3)
diameter of the inner cylinder = 8 cm = 0.08 m (100 cm = 1 m)
radius of the inner cylinder = diameter/2 = 0.08/2 = 0.04 m
area of the inner cylinder = 
where
= 3.142,
and r = radius = 0.04 m
area of inner cylinder = 3.142 x
= 0.005 m^2
<em>height h of the water in this cylinder = volume/area</em>
h = 0.002/0.005 = 0.4 m
<em>pressure at the bottom of the cylinder due to the height of water = pgh</em>
where
p = density of water = 1000 kg/m^3
g = acceleration due to gravity = 9.81 m/s^2
h = height of water within this cylinder = 0.4 m
pressure = 1000 x 9.81 x 0.4 = <em>3924 Pa</em>
Answer:

Explanation:
In order to calculate the angular momentum of the particle you use the following formula:
(1)
r is the position vector respect to the point (0 , 5.0), that is:
r = 0m i + 5.0m j (2)
p is the linear momentum vector and it is given by:
(3)
the direction of p comes from the fat that the particle is moving along the i + j direction.
Then, you use the results of (2) and (3) in the equation (1) and solve for L:

The angular momentum is -30 kgm^2/s ^k