Recent content by waverider

Yes, a good point to bring up - I have recently seen some people on YT make this very mistake.

Great! thanks for the confirmation and equations. Yeah, I have seen the sports curling...fun to watch, and I agree the math could get very nasty.

If I push an object such as a cylinder of wood along a flat table (flat face of cylinder in contact with the table) through it's center of mass, the friction or energy required is not dependent of the surface area the block makes with the table, Friction = μ N, correct? And the energy required =...

Indeed, the Wikipedia weight is 7.3 times higher. I find it impossible that Cavendish was able to measure such a tiny force of attraction between the metal spheres and this force was able to overcome the air resistance and mechanical friction which was apparent in the apparatus.

According to Wikipedia, Cavendish was able to measure a force of 1.74E-7 N or “roughly the weight of a large grain of sand[13] of 0.13 mg” However, with my calculations using m=F/g, where g=9.81m/s/s Gives m=1.74E-7/9.81 = 1.77E-8 kg = 0.0177 mg Which is much less than 0.13 mg Am I missing...

Thanks, a real life example makes it easier to visualize I wounder if F=m(dot).v could be applied to a spray can that is spraying gas at the rate of m(dot) and gas velocity v, would the nozzle experience a force, (disregarding the air pressure and friction) ?

Cool, thanks

Thanks. So for water flowing through a pipe (kg/s) at constant velocity, what does the force calculated by m(dot).v represent? is it the frictional force on the pipe?

I know that F=ma which give the units of kg.m/s/s (in SI units) but can force also be expressed as mass flow rate times velocity which also has the same units? Example: water coming out a hose or gas coming out a spray can?