Recent content by damitr

What is the lowest intensity of light that generates any stimulus in the human eye? In what wave length range?

''He gets tired, sure, but that's his problem. '' This is precisely what I meant to ask... What happens to the energy expended by the person [sure he expends some energy as he feels exhausted] as there is no work done. To put it in other words, try to lift a very heavy load off the...

A person is sitting in a heavy cart with wheels. The person pulls a rope attached to a rigid support, but the cart does not move. Where does the energy expended by the person go? Is it converted into heat or stored somewhere as potential energy, please clarify?

The information needed would be the velocity of the bullet as it leaves the rifle, height at which the monkey is present. I was unaware of the practice of ''sighting in''. But does that mean an experienced hunter can miss a target, if the location of hunting changes (changing the g value)?

Ok The hunter misses the target in gravity, but then how does one get a correct shot?

The classical monkey and the hunter paradox goes something like this : A monkey sitting on a tree top is aimed at by a hunter. As soon as hunter shoots the monkey jumps down. The bullet hits the monkey even when it has jumped because they both fall with same acceleration viz. g. My...

Even building up an invisibility device, would make person invisible (if possible ) 'only' in some wavelength range. The device MUST radiate at some wavelength or the other , which will be related to its temperature (BBR).

Consider collision of two bodies of mass m1 and m2. m2 is at rest whicle m1 moves with velocity v1. When they collide they sitck together. The question is what is the final velocity V of the two bodies combined. This apparently simple problem if solved naively leads to an apparent paradox if...

All the rainbows that appear naturally, are usually semicircles, what is the reason for this, they could also be as little arcs as well. Are there any conditions under which a complete circle of the rainbow may be seen?

Violation of Newton's Third Law. The examples that I have quoted are from the book Elementary Physics by I. P. Guruskii (Mir Publishers 1987) pg. 55. How do these examples violate the law? That is what I want to know ... The book does not give any explanation for these 'violations'...

Are there any examples of violation of Newton's third law? The two examples that I know are : 1) Two masses moving relativistically apart from each other. 2) Two charges moving in mutulally perpendicular directions. Can anybody further elaborate on these exmaples with proper explanation and...

As you have said "the net force includes gravity, so no need to mention potential energy." I have not understood this statement of yours. What do you exactly mean by ? Do we not have to take into consideration the potential energy that has been changed ? And from what I have learned...

Even with the modified definition "The net work done by all the forces acting on a body equals the change in its kinetic energy." it still does not answer the quastion even here is no mention about the change in potential energy, only kinetic energy is mentioned and that's what the real...

Well that's the problem the theorem says that only the kinetic energy changes whereas in this case the potential energy also changes

The work energy theorem says that ''The work done by the net force acting on a body results change only in its kinetic energy. '' But if the resultant force is in vertically up direction it will surely change its potential energy too, so what's the solution here.