Two thin converging lenses of the focal lengths 30 cm and 40 cm are placed coaxially 20 cm apart. an object is located at a distance of 48 cm from the first lens. find the positions of the principle points of the lens combinations and indicate these positions in a diagram

In which of the following cases is work being done on an object? question 2 options: pushing against a locked door carrying a box down a corridor pulling a trailer up a hill suspending a heavy weight with a strong

Carbon is allowed to diffuse through a steel plate 15 mm thick. the concentrations of carbon at the two faces are 0.65 and 0.30 kg c/m^3 fe, which are maintained constant. if the preexponential and activation energy are 6.2 x 10-7 m2 /s and 80,000 j/mol, respectively, compute the temperature at which the diffusion flux is 1.43 x 10^-9 kg/m^2 -s.

Holes drilled several kilometers into earth’s crust provide direct evidence about earth’s interior in the form of