### Calculating Velocity

Posted:

**Sun Dec 09, 2018 2:24 pm**This is the equation you would use for this correct? because p= mv?

Created by Dr. Laurence Lavelle

https://lavelle.chem.ucla.edu/forum/

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=18&t=39342

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Posted: **Sun Dec 09, 2018 2:24 pm**

This is the equation you would use for this correct? because p= mv?

Posted: **Sun Dec 09, 2018 3:27 pm**

yes and you could also use ke=1/2mv^2

Posted: **Sun Dec 09, 2018 3:56 pm**

yes, the two equations involving velocity are p=mv and KE= 1/2mv^2

Posted: **Sun Dec 09, 2018 5:37 pm**

Make sure you know the Difference!!!

p=mv is for the velocity of a photon, he will usually give you the momentum.

Ke is for Electrons!

p=mv is for the velocity of a photon, he will usually give you the momentum.

Ke is for Electrons!

Posted: **Sun Dec 09, 2018 5:53 pm**

What is the units for momentum, p?

Posted: **Sun Dec 09, 2018 5:54 pm**

If the mass is in kilograms and the velocity is in meters per second then the momentum is in kilogram meters per second (kg⋅m/s)Lynsea_Southwick_3F wrote:What is the units for momentum, p?

Posted: **Tue Jul 02, 2019 11:27 am**

Most of the time we use 1/2mv^2 to calculate velocity.

Posted: **Tue Jul 02, 2019 12:52 pm**

It depends on different condition, like if you need to calculate the velocity, and you have time and distance, you can use the most common equation:v=s/t, and if you have the momentum and mass of a subject, and you need to calculate the velocity, you can use the equation you have mentioned.

Posted: **Wed Jul 03, 2019 11:07 am**

Depends on the know information you have. If you know the kinetic energy of an electron then you could use 1/2mv^2 or if you know the momentum of the electron then you could use p=mv. Also the units for momentum would be kg.m.s^-1.

Posted: **Sun Jul 07, 2019 10:54 pm**

electrons use ke, photons use the momentum equation