The basic relationship between frequency and wavelength for light (which is an electromagnetic wave) is

where c is the speed of light, f the frequency and

the wavelength of the wave.
Using

and

, we can find the value of the frequency:
Answer:
201.5537 mph
Explanation:
Given the following data;
Speed = 90.1 m/s
Speed can be defined as distance covered per unit time. Speed is a scalar quantity and as such it has magnitude but no direction.
Mathematically, speed is given by the formula;
Speed = distance/time
To convert this value into miles per hour;
Conversion;
1 meter = 0.000621 mile
90.1 meters = 90.1 * 0.000621 = 0.05595 miles
1 metre per second = 2.237 miles per hour
90.1 meters per seconds = 90.1 * 2.237 = 201.5537 miles per hour
90.1 m/s = 201.5537 mph
Answer:
W = 157.5kJ
Explanation:
Assuming it moves the container at constant speed, the work done by the crane will be equal to the variation of the potential gratitational energy on the container:
where h2= -8m and h1=0m
Wc = 157.5kJ
Answer:
Advantages of Hydroelectric Energy
1 Renewable
Hydroelectric energy is renewable. This means that we cannot use up. However, there’s only a limited number of suitable reservoirs where hydroelectric power plants can be built and even less places where such projects are profitable.
2 Green
Generating electricity with hydro energy is not polluting itself. The only pollution occurs during the construction of these massive power plants.
3 Reliable
Hydroelectricity is very reliable energy. There are very little fluctuations in terms of the electric power that is being by the plants, unless a different output is desired. Countries that have large resources of hydropower use hydroelectricity as a base load energy source. As long as there is water in the magazines electricity can be generated.
4 Flexible
As previously mentioned, adjusting water flow and output of electricity is easy. At times where power consumption is low, water flow is reduced and the magazine levels are being conserved for times when the power consumption is high.
5 Safe
Compared to among others fossil fuels and nuclear energy, hydroelectricity is much safer. There is no fuel involved (other than water that is).