A power meter is a device fitted to a bike that measures the power output of the rider.
Most commonly, power meters use strain gauges that deflect slightly when a force is applied. By measuring this torque and combining it with angular velocity, power (measured in watts) can be calculated.
Answer: E. None of the above
Explanation: The energy of a photon is given by the formula below.
E=hf or E = hc/λ
E = energy, h = planck constant, c= speed of light and
λ= wavelength.
From E=hf we can see that energy is directly proportional to frequency since h is a constant, this implies that as we move up the visible light spectrum, red light has the least frequency this accounting for the lowest energy while violet has the largest energy accounting for a very high energy.
Blue light is higher in the spectrum than red light.
This implies that blue light has more energy than red.
Visible light is part of the electromagnetic spectrum which implies that they all travel with the same speed of a constant value ( speed of light = 3* 10^8 m/s).
Thus in conclusion, blue light has more energy that red light but they both travel with the same speed.
This point nullifies the options thus making none of it correct.
