# Non relativistic approach

This forum made possible through the generous support of SDN members, donors, and sponsors. Thank you.

#### determined daisy

##### Full Member
7+ Year Member
1) Consider 3rd orbit of He+ (Helium), using non-relativistic approach, the speed of electron in this orbit will be [given K = 9 x 109 constant, Z = 2 and (hfPlanck's Constant) = 6.6 x 10-34 J s]

A) 2.92xl06m/s B) 1.46xl06m/s
C) 0.73xl06m/s D) 3.0xl06m/s

2. Relevant equations
V=C/137 multiplied by Z/N
Here V=velocity of electron
C=3 multiplied by 10^8
N=number of orbit
or 2.18 multiplied by 10^6

3. The attempt at a solution

Now if i will solve for this i will get my answer as option B.But I want to know what non-relativistic approach means?I have googled it but did not get anythIng.PLEASE GUIDE..

Members don't see this ad.

Non-relativistic means that you do not need to include the affects of special relativity in this scenario. The MCAT will never ask you to formula a relativistic answer as that is out of the score of the test.

However, if you are curious, some of the more general solutions we have developed for solving physics problems break down when the object in question is approaching the speed of light. For example, when speed in increased to a non-trivial fraction of the speed of light, the momentum (and therefore relative weight) of the object will be higher than expected, the kinetic energy of the object will be higher than expected, the object will undergo time dilation (a second traveling at that speed will be longer than a second on a stationary object), and the object will appear contracted relative to a stationary observer.

tl;dr - non-relativistic means to continue the status quo and not try to do anything funky