Posted by **Tiffany** on Tuesday, June 2, 2009 at 3:12pm.

do gamma rays carry momentum? i thought they dont because they dont have mass so mv=0 but my frend says even tho they dont have mass they still carry momentum. how does this make sense? please help.

- momentum -
**Damon**, Tuesday, June 2, 2009 at 3:32pm
Photons in general carry momentum so any electromagnetic wave has momentum associated with it despite its lick of rest mass in the classical sense. If a photon hits something, it moves it.

E = energy of photon = m c^2 = h f where c is velocity of light and h is plank constant and f is the frequency

Of course we know classical rest mass m is zero but that does not prove there is no energy, m c^2 at the velocity of light.

then m c = momentum p

but m c = E/c

so p = E/c

but E = h f

so

momentum p = h f /c

but f/c = 1/Tc = 1/Lambda

where T is period and Lambda is wavelength

so

p = h/Lambda

## Answer This Question

## Related Questions

- physics - Will check my work and help me with the last two problems please? A 4 ...
- Physics - Will you check my work and help me with the last two problems please? ...
- Physics Problems - Will check my work and help me with the last two problems ...
- physics - Explain how it is possible for a motorcycle (mass = 250 kg) to have ...
- Physics - A child throws a snowball at a tree and it sticks to the tree. Does ...
- physics - A cart of mass 340 g moving on a frictionless linear air track at an ...
- Physics - Two masses, m1 = 2.0 kg and m2 = 3.3 kg, are moving in the xy-plane. ...
- Physics - I think I chose the correct answer. In a closed system, two carts have...
- Physics: Collison/Momentum Problem - A 15 kg mass, moving east at 5 m/s, ...
- physics - Which one of the following statements is true for two bodies having ...

More Related Questions