Recent content by D. Wani

What is the difference between angular and linear magnification

What are the different formulas for the calculation of magnifying power of a microscope and a telescope? And how would we use the sign conventions in them?

Thanks

This is the answer I was looking for. Thank you. I basically wanted to know what negative and positive work are in terms of energy loss and gain.

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Thank you, everyone

If a body is falling downward under the effect of gravity(=mg) and someone applies a force(=mg) in the opposite direction (upward), then the body will continue moving downwards as the net force is zero. What would be the magnitude of the force applied such that the body would freeze in midair(if...

Can work done against gravity be negative? (In the sense that the angle between displacement and force is zero)

What if we had to analyze whether a particular force was doing positive or negative work?

I had a question about positive and negative work, too. Could you please check it out? https://www.physicsforums.com/index.php?threads/851409/

Though work is only done when there is displacement of the body

But, as cnh1995 said, for the body to be set into motion, the initial force has to be in infinitesimally greater than mg, just at that instant.. After that, to maintain constant speed, we need to apply a force equal to (mg). Right?

I got a little confused?

We are concluding all of this assuming friction and air resistance are absent, right?

So, when we consider the force applied by the person to be zero, and we calculate work done, we are just calculating the work done in moving the body against gravity, not in increasing its kinetic energy or in accelerating it? Work done in moving a body against gravity and work done in...