Recent content by cavis

Hi there, I'm having a little confusion regarding spherical aberration from some experiments I've been doing with a concave mirror. I've been directing the mirror so that it faces the distance (ie. objects at infinity) and then positioning a flat piece of paper so that an image forms on it. The...

Thank you for the response, Simon. It helps a lot. May I ask another quick question? A classic demo involving waves on a string is to attach a vibrator to one end of the string whose other end is a fixed end. The vibrator oscillates up and down with a very small amplitude (so this end of the...

Hi all, I've got a question about waves and standing waves on a string fixed at both ends. I understand why only certain discrete wavelengths / frequencies are allowed to generate standing waves on a string such as a guitar string. My question pertains to understand what happens when a guitar...

Hi there, I've got a fairly simple question theoretical question about transformers and I suspect it stems from a misconception I have about them. I understand that step down transformers can be used in situations where a high current is desired but that they also reduce the voltage in the...

Thanks, Jano. This helps. Just to clarify, if the disk we just suspended at its lowest point without rotating, the hinge force would be equal to mg? But, since it's rotating and a radially directed centripetal force is required, the hinge force must exceed mg? Do I have that correct? If I...

Hi there, I've got a conceptual question about the normal force as applied to rotational motion. Suppose you have an object like a uniform disk. If the disk were set up so that its axis of rotation were about its centre of mass, it would just sit there and the normal force would be equal to...

Thanks cmos and M Quack. Those responses really helped. Regards, Chris.

Greetings, I am a Physics instructor teaching a course on Physics for Medical Radiologists and have a question to further my own understanding of wave / particle behaviour of X-Rays as used in x-ray image production. My background is more in climate / geophysics. The textbooks available for...