To Do or Not To Do

- Hey, Professor! When you were saying that there was homework, did you mean that we had to do it?

I needed a moment to comprehend that question.  

Dear Student, I designed and posted the HW assignment just because I like to post something from time to time and apparently I did not have anything better to do yesterday.  

An end-of-semester message

No kidding!

Relativity of Time

Where physics meets philosophy... There is another view on the relativity of time: 

Growing older is mandatory.  

Growing up is optional.

Just a thought dedicated to my students.

Torque

The picture above shows two masses in an equilibrium. Physicists see this situation through the lenses of forces and their respective arms (an arm is the distance from pivot point to the point where the force is exerted).

 counterclockwise torque (the left side) = 26 cm * 100 g = 2600 cm*g

clockwise torque (the right side) = 13 cm * 200 g = 2600 cm*g

Accelerated motion

The time of glider passing between photogates is measured with high accuracy (0.001 s). 

The same video in low motion: