Answer:
Explanation:
Potential at a point near a charge = Q / 4πε₀ R
where Q is charge given , R is distance of point from the charge .
Q / 4πε₀ R = 40
Electric field E at A = -dV / dR
= .16 x 10⁻³ / 2 x 10⁻⁶
= .08 x 10³
= 80 N/C
E = Q / 4πε₀ R²
80 = Q / 4πε₀ R x R
80 = 40 / R
R = 40 / 80
= .5 m .
Answer:
Power = 251.9 Watts
Explanation:
Power = Work Done / Time taken
Power = 3441 / 13.66
Power = 251.9 Joule / Second
Power = 251.9 Watts
Answer:
<em>a) A positive current will be induced in the coil</em>
Explanation:
Electromagnetic induction is the induction of an electric field on a conductor due to a changing magnetic field flux. The change in the flux can be by moving the magnet relative to the conductor, or by changing the intensity of the magnetic field of the magnet. In the case of this electromagnets<em>, the gradual increase in the the electromagnet's field strength will cause a flux change, which will in turn induce an electric current on the coil.</em>
According to Lenz law, the induced current acts in such a way as to negate the motion or action that is producing it. <em>A positive current will be induced on the coil so as to repel any form of attraction between the north pole of the electromagnet and the coil</em>. This law obeys the law of conservation of energy, since work has to be done to move the move them closer to themselves.
Answer:
Explanation:
Impulse on an object is given by ![\mathrm{[impulse]}=F\Delta t](https://tex.z-dn.net/?f=%5Cmathrm%7B%5Bimpulse%5D%7D%3DF%5CDelta%20t)
.
However, it's also given as change in momentum (impulse-momentum theorem).
Therefore, we can set the change in momentum equal to the former formula for impulse:
.
Momentum is given by 
. Because the truck's mass is maintained, only it's velocity is changing. Since the truck is being slowed from 26.0 m/s to 18.0 m/s, it's change in velocity is 8.0 m/s. Therefore, it's change in momentum is:
.
Now we plug in our values and solve:
(two significant figures).
Divide the flow rate (0.750 m³/s) by the cross-sectional area of each pipe:
diameter = 40 mm ==> area = <em>π</em> (0.04 m)² ≈ 0.00503 m²
diameter = 120 mm ==> area = <em>π</em> (0.12 m)² ≈ 0.0452 m²
Then the speed at the end of the 40 mm pipe is
(0.750 m³/s) / (0.00503 m²) ≈ 149.208 m/s ≈ 149 m/s
(0.750 m³/s) / (0.0452 m²) ≈ 16.579 m/s ≈ 16.6 m/s
