Answer : The correct options are, (B) a newton-meter and a joule and (C) a newton and a joule/sec
Explanation :
As we know that,

or we can say that,

From the given options, the option B and C are the equivalent units.
Hence, the correct options are, (B) and (C)
Speed = Distance/Time = 100 km / 4 hours = 100/4 km per hour = 25 kph
Answer: The reason a light bulb glows is that electricity is forced through tungsten, which is a resistor. The energy is released as light and heat. A conductor is the opposite of a resistor. Electricity travels easily and efficiently through a conductor, with almost no other energy released as it passes.
Explanation:
Answer
Voltage is how fast the electrons flow. Power is a use of voltage times the volumes of electrons. The higher the voltage the more power you have with the same current.
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