# Question #638fc

Oct 17, 2017

Gosh! How long have you got?

#### Explanation:

Students find it difficult to appreciate the difference between angular and linear velocity. They don't 'like' omega (angular frequency) at all and find it difficult to calculate given just a frequency or period, especially if the information is presented graphically. They forget the minus sign in the equation $a = - {\omega}^{2.} x$ quite often too and lose marks there.

Students also get nervous because sometimes the question appears to give very little information so they don't know how to proceed, or forget the basics ($T = \frac{1}{f}$ etc.) in their (understandable) panic.

It also links into lingering misconceptions over Newton's laws and energy transfer (e.g. calculate the force of the Earth on the moon. State how much force the moon applies to the earth OR how much work is done on/by a satellite in orbit around the earth.)

There really is a list of these ... sorry ... but these are some of the most common.