Aboy 1m tall looks at the swimming pool, which appears to be 75 cm deep, according to the people around him. he finds himself almost completely submerged in water when he steps into the water. was he tricked? how did it happen?

Matter that emits no light at any wavelength is called

It may seem strange that the selected velocity does not depend on either the mass or the charge of the particle. (for example, would the velocity of a neutral particle be selected by passage through this device? ) the explanation of this is that the mass and the charge control the resolution of the device--particles with the wrong velocity will be accelerated away from the straight line and will not pass through the exit slit. if the acceleration depends strongly on the velocity, then particles with just slightly wrong velocities will feel a substantial transverse acceleration and will not exit the selector. because the acc

What are the dimensions of the cross section that passes through the points a, f, g, and d?