Recent content by NA19

Where is the other pi?

Homework Statement A plane polarized electromagnetic wave propagates with Erms = 30 V/m. What is the power transmitted to a circular disk of radius r = 2m, if all of the light is absorbed by the disk and S is perpendicular to the disk? Homework Equations There is a passage that goes...

So are the black lines that I drew correct for the line of force? And the red for the lever arms?

So, as anything increases in height above the ground, its apparent weight increases? For example, if I lifted an 8 pound weight, it would feel like it was heavier the higher I lifted it?

So if you're accelerating upwards, wouldn't your apparent weight be less?

So wouldn't that just be the normal force which is equal to mg? Mathematically, it seems that his weight would decrease because gravity is acting on him pulling him downwards (mg) and the plane is pulling him up faster than gravity is pulling him down (mg + x). So his apparent weight would be mg...

So is the lever arm the forearm?

Homework Statement The diagram is attached. It is asking which position has the greatest lever arm.Homework Equations The Attempt at a Solution So, I know that the elbow is the fulcrum but what I'm struggling with is how to draw the force arrow. Where is the force coming from and where is it...

Homework Statement While pulling out of a dive, does a pilot's apparent weight increase or decrease? Homework Equations The Attempt at a Solution My instinct for this question says increase but only because of the feeling that I remember from being in planes. I'm trying to grasp...

Okay, but... Isn't B farther away from the pivot point than A in position 1? Why are we ignoring everything but the top pulley.

So you would equate mgsintheta = mv^2/r? And then since speed increased, you would also need to increase theta? What is the conceptual explanation? Why would the angle need to be increased if the speed increases?

Q1) The total toque on the pulley is zero. Q2) Forces farther away are less than when they are close. I kind of understand what is happening right now, but a few more questions: How do you determine that this is a lever question instead of a pulley question? I don't really understand how...

Homework Statement The question is attached! Homework Equations mgsintheta = downward force on incline The Attempt at a Solution I was thinking that this has something to do with the downward force on the incline and making sure that the car doesn't slide down the incline. Changing...

Why isn't the pivot in the middle? Why isn't the pulley moving?

I tried that, but I am not sure how the pulleys and the arrow would affect the forces acting on the strings. My initial instinct was that the tension in A is greater than the tension in B in position 1 because A seems more stretched. Then, I thought that the tension is the same in position 2...