1:41 AM
1

I understand why rolling motion does no work. My (possibly imprecise) summary of the answer is that net work done is zero. And the role of friction is to convert translational kinetic energy into rotational kinetic energy. (I am not interested in the specifics of that conversion - though it is b...

8 hours later…
10:05 AM
2

So I understand that a lower gear as advantageous when accelerating a vehicle or when driving up hill (e.g because you are having to accelerate against gravity). I know this is because of the increased torque measured at the gearbox output due to to the leverage ratio provided by the gearbox, so ...

6 hours later…
3:47 PM
1

A sphere lies on a frictionless, horizontal surface. A horizontal force is applied to the sphere (but above or below its center of mass). Will the sphere roll or slide? (I think it will roll based on this answer) If it does roll, then will the acceleration be different compared to if the force i...

2

I've heard the example, that work is path dependent. But whether I climb a mountain directly or in serpentines, in the end it's the same amount of work, with the one difference that it takes me longer to climb the serpentines, but in the end I've done the same amount of work against gravity as if...

4 hours later…
7:36 PM
4

My chemistry knowledge is of a high-school level. In high-school, the properties of atoms were mostly presented as empirical phenomena. We learned some physical principles such as the idea that covalent bonds are based on exchanging electrons and that there are always 8 possible electron "slots" ...

2 hours later…
9:30 PM
5

What would your reflection look like if a mirror was going close to the speed of light? Conditions: The mirror is a very long perfect mirror, lets say a light year long, moving close to the speed of light perpendicular to the line of sight the observer is looking. This is so that the distance bet...