Unless the boy is on another planet, the problem as stated makes no sense. With Earth's gravity (a=-9.8m/s^2) being the only influence on the ball, at the end of 3 seconds it will be   h = v₀t - (1/2)at² = 20(3) - (1/2)(9.8)(3^2) = 15.9 meters above where it was thrown from. The surface … Read more

Hmm, thnanks again

Thank-you so much sir. But still I am not able to understand how this "d(load power)/dRl = Vs^2*(Rs-Rl)/(Rs+Rl)^3" has been differentiated and how you concluded Rs = Rl..

You need to be a little careful in your thinking about this and in the terminology you use to describe the situation. In a two-terminal linear circuit that can be modeled by a constant supply voltage source (Vs) and a constant source impedance (Rs), the maximum power dissipation will occur when the two terminals are … Read more

750W/240V = 3.125A A 1A or 3A fuse would be too small. If the fuse is in the iron, a 5A fuse might be appropriate. _____ The correct size of a fuse depends on what the fuse is intended to do. In house wiring, the fuse is intended to protect the wiring and to reduce … Read more

With the side of one foot pressed against the wall, you cannot get your center of gravity over that foot, especially so if you lift your leg in a direction that is out from the wall. If you have a very wide foot, you may be able to turn your leg so your body (chest … Read more