A small red light-emitting diode (LED) is placed 15.0 cm below the surface of the water in a bathtub. Because of total internal reflection, a circle of red light is observed at the water surface. Light inside the circle gets out into the air, but light hitting the water surface (from below) outside the circle experiences total internal reflection. Calculate the diameter of this circle. Assume that the air above the water has an index of refraction of 1.00, and that the water has an index of refraction of 1.33. diameter

Tom is having a problem with his washing machine. he notices that the machine vibrates violently at a frequency of 1500 rpm due to an unknown rotating unbalance. the machine is mounted on 4 springs each having a stiffness of 10 kn/m. tom wishes to add an undamped vibration absorber attached by a spring under the machine the machine working frequency ranges between 800 rpm to 2000 rpm and its total mass while loaded is assumed to be 80 kg a) what should be the mass of the absorber added to the machine so that the natural frequency falls outside the working range? b) after a first trial of an absorber using a mass of 35 kg, the amplitude of the oscillation was found to be 10 cm. what is the value of the rotating unbalance? c) using me-3.5 kg.m, find the optimal absorber (by minimizing its mass). what would be the amplitude of the oscillation of the absorber?

The quality is zero at a)-the saturated vapour state b)-the saturated liquid state c)-the saturated liquid-vapour mixture state d)-none of the states in the other answers

Explain the strain-hardening phenomenon on the basis of dislocation - dislocation strain field interactions. also, briefly describe what generally happens to the ductility of a metal that has been strain hardened (i.e. does strain hardening make a metal more ductile or