Calculating wavelengths, frequency, ....etc

Question

Hello, i couldn't do this questions correctly. please answer in full settings thank you so much =]

1.) the average ultra violet photon has a frequency of 10^16 Hz, the average visible light photon 10^15Hz and the average infra red phton 10^12 Hz. According to Neils Bohr the energy of a photon is given by E = hf where h is a constant number.

a.)Which energy is the fastest?

b.)by what factor is ultra violet light more energetic than heat?

c.) which of there causes sunburn?

2.) Waves spaced 10m apart hit a beach at 4 seconds intervals. Find

a.)the period

b.) the frequency

c.) the velocity

3.) A primary earthquake wave travels 8km sec-1 and has a period of 0.2sec. Find

a) how long it would take to travel 160km

b)its wavelength

c)Its frequency

Answer 1

1)

a) highest energy is ultra violet which has highest frequency. For the fstest, they have same speed

b)heat given by IR so 10^16/1012= 10^4

c)Ultraviolet cause sunburn

2) a) period 4 s

b) frequency 1/4s

c) 10/4=2.5m/s

3) a) 160/8=20s

b) wavelength = c*T=8*0.2=1.6km

c) frequency 1/period= 1/0.2=5 Hz