Recent content by DrnBrn

Hello Everybody! I have a question - If I'm standing inside a train and I jump up in the air I will land in the same place, I think. Likewise, if I'm holding a pen in my hand and I throw it up in the air it will land again in my hand. But if I stood on top of the train, on the roof, and I...

Hi I'm not a physicist but I'm looking for a simple way to test the hardness of different materials. I need to do a demonstration and collect results with a science class, the task sheet that accompanies the lesson says to place a cloth over the materials and hit them with a hammer. I would...

Hello everyone I have question on very basic physics: I'm thinking about simple analogies to explain current flowing in a simple series circuit. One analogy I have looked at has a bread factory making bread and loading it onto a truck. Each time a truck passes the bread factory it takes...

I've drawn out the circular orbits and worked it out. Thanks for your help.

Thanks. Assuming the orbits are circular makes a lot more sense. So, I suppose the distance when the planets are closest is 1.5 x 10e8 (radius Earth's orbit) - 1.1 x 10e8 (radius venus' orbit). And when they're farthest apart the distance is the difference calculated above + the diameter of...

Hi I'm a bit confused, I hope you can help. The question is - In the course of their orbits, the distance between the Earth and Venus changes. The radii of the orbits of the two planets are 1.5 x 10e8 km and 1.1 x 10e8 km. If a radio pulse is transmitted from Earth towards Venus, calculate...