Question

You were driving your car to UTD at a speed of 35 miles per hour. You stopped at the FloydCampbell intersection with the signal light showing red (wavelength = 6.45 × 10–5 cm). After 30 sec, the signal becomes green whose frequency is 5.80 × 1014 s –1 . Which light has higher energy?

Answer 1

green light have high energy

Step-by-step explanation:

We have given the wavelength of the red light
`\lambda =6.45* 10^(-5)cm=6.45* 10^(-7)m`

Speed of the light
`c=3* 106{8}m/sec`

The energy of the signal is given by
`E=h\\u =h(c)/(\lambda )=(6.67* 10^(-34)* 3* 10^(8))/(6.45* 10^(-7))=3.1023* 10^(-15)j`

The frequency of the green light is given by:

`f=5.80* 10^(14)s^(-1)`

So energy
`E=h\\u =6.67* 10^(-34)* 5.80* 10^(14)=3.8686* 10^(-19)j`

So green light have high energy