1:03 AM
3

Suppose you drag a piece of sandpaper along the surface of a wall(let's keep it simple). Here you are doing positive mechanic work on the sandpaper, this makes it gain energy. Friction does negative work on the sandpaper which makes it lose energy. Now, we know that bcz the sandpaper is in motion...

15 hours later…
3:44 PM
2

Suppose two bodies $A$ and $B$ with equal mass are kept at a distance. $A$ starts moving towards $B$ at a constant velocity, they hit, and I assume that it is a PERFECTLY INELASTIC collision here. According to what I learnt from my book, suppose a body hits another body and inelastic collision ta...

5 hours later…
9:04 PM
2

The moment of inertia is defined as $$I = \int r^2 dm$$ but I am not sure how to proceed with solving the above integral. All examples I have seen seem to be done with different strategies. They usually start: "well consider this part of the mass $dm$" and then suddenly just plug in $2 \pi r$ an...

2 hours later…
10:49 PM
2

I read in many sites that the concept of mechanical energy is the ability of an object to do work, but how can an object do work? Isn't it rather the force applied to that object the one that produces work and not the object itself?. We can have an object that has mass $m$ and a constant speed \$v...