Answer:
I haven’t done this in a while but i think b
Explanation:
B because it conducts electricity which means it contains a metal hope this helps
Explanation:
Sorry if I toke a while (needed to finish some work) but here you go!!! :D.
"The potential on the surface of a conductor is always zero."
This statement is false. A good number of times we define a point's potential to be the amount of work that must be done to move 1 coulomb of charge from infinitely far away to that point. So if, let's say, the conductor had a net positive charge, then you would need to do a net positive amount of work to move 1 coulomb of charge from infinitely far away to any point on the conductor's surface. We have just provided a case for which the potential on the surface of the conductor is not 0.
Answer: V = 15 m/s
Explanation:
As stationary speed gun emits a microwave beam at 2.10*10^10Hz. It reflects off a car and returns 1030 Hz higher. The observed frequency the car will be experiencing will be addition of the two frequency. That is,
F = 2.1 × 10^10 + 1030 = 2.100000103×10^10Hz
Using doppler effect formula
F = C/ ( C - V) × f
Where
F = observed frequency
f = source frequency
C = speed of light = 3×10^8
V = speed of the car
Substitute all the parameters into the formula
2.100000103×10^10 = 3×10^8/(3×10^8 -V) × 2.1×10^10
2.100000103×10^10/2.1×10^10 = 3×108/(3×10^8 - V)
1.000000049 = 3×10^8/(3×10^8 - V)
Cross multiply
300000014.7 - 1.000000049V = 3×10^8
Collect the like terms
1.000000049V = 14.71429
Make V the subject of formula
V = 14.71429/1.000000049
V = 14.7 m/s
The speed of the car is 15 m/s approximately