PHYS 132 Lecture 21: Lecture 21 Notes

The eye can detect as little as 10^-18 J of energy in the form oflight. How many photons of frequency 5 x 10^14 Hz does this amountof energy represent?

Am I supposed to convert something? I feel as if I am over thinkingthis a little bit.

1. A sphere has a radius of 21 cm and a mass of 1.9 kg. Itsmassdensity is about:
(1) 49 kg/m3 (2) 2.0 £ 10¡6 kg/m3 (3) 2.0 £10¡2 kg/m3 (4) 1.4 kg/m3(5) 14 kg/m3

1. A sphere has a radius of 21 cm and a mass of 1.9 kg. Itsmassdensity is about:
(1) 49 kg/m3 (2) 2.0 £ 10¡6 kg/m3 (3) 2.0 £10¡2 kg/m3 (4) 1.4 kg/m3(5) 14 kg/m3