Recent content by BadatPhysicsguy

Homework Statement We have the set D which consists of x, where x is a prime number. We also have the set F, which consists of x, belongs to the natural numbers (positive numbers 1, 2, 3, 4, 5..) that is congruent with 1 (modulo 8). What numbers are in the intersection of these two sets...

Hm, so the volume of the "large thin cylinder" is simple geometry, right? The radius is 2 (from 0->2) and the height is 1/2. So that would be 2^2*pi*1/2. So 2*pi or approx 6.28 is the total bottom part. As for the remaining part, I have to integrate. It must be expressed as x^2, so yx=1 =>...

Hello and thank you for another answer. Tell me if I'm understanding this correctly. So looking from above, I see a volcano. From above, the radius of the "hole" is from x=0 to x=1? The part between yellow and green is the "rock" part of the volcano and then there is a steep fall from the edge...

So first I'd take the total volume under the purple line. But how do I get the volume that is between the purple line and the blue curve? Purple minus blue and then the total volume under purple minus whatever I got from the second one?

Homework Statement An area is enclosed by y=1/x, the positive x-axis and x=1 and x=2. Determine the volume of the rotational body that is created around the y-axis. Homework Equations The formula is pi*integrate from d to c for x^2 dx. The Attempt at a Solution Take a look here...

Homework Statement The curve y=1/x and the line y=2.5-x enclose an area together. Determine the exact volume of the rotating body that is formed when this field rotates about a) The x-axis and b) The y-axis Homework Equations The formula for rotation around the x-axis is pi*integrate from b to...

Hello, yes I forgot that! I calculated z degrees and then got x to be 45 degrees (making y also 45). So the depth is the same as the base of the triangle, approx 4 meters.

Hello and thank you for your answer. But if the ray comes from the very center of the stone and it is truly in the edge of the pool, shouldn't it be "like" 45 degrees from the pool's wall down to the center of the stone? And if the ray just grazes the edge of the pool, I then get this...

Hello! Thank you for your answer. I did draw a normal perpendicular to the water's surface. But if is measured from the normal to the refracting surface aren't both angles 90 degrees then?

Homework Statement An object is mirrored in a concave mirror. Construct the image of the object using two rays from the object. (draw in the picture) Homework Equations None needed? The Attempt at a Solution So the upward arrow is the object, f is the focal point I assume. I am to draw two...

Homework Statement A stone lies to the very edge at the bottom of a pool. The pool is filled with water to the top. The person standing three meters away from the pool is 1 meter tall and he can see exactly the half of the stone. Calculate the depth of the pool.Homework Equations Snell's law...

We have been taught to think that way. Is there any other way?

Now that I've checked solutions, it appears that the component that goes to the "right" is from the cable and Earth's magnet field upwards, even though the problem states the magnetic field's effect is horizontal. Why?

With vertical I mean the component that goes with the cable. I don't really know how the compass needle moves, I can only assume it deviates 72 degrees from whatever point it started, but I don't know if it is to the right or the left. How do I think here?

Homework Statement We have three equally long conductors with equali distance between each. I have simply drawn it badly. The difference is their currents, they all go in the same direction. How is the middle one effected? - It goes to the right - It goes to the left - It goes up from screen...