The maximum electron energy in a photoelectric experiment is 2.8 eV. When the frequency of the illuminating radiation is decreased by 50%, the maximum electron energy drops to 1.1 eV. Find a) the original wavelength (and frequency) of the illuminating radiation and b) the work function of the emitting surface

Which diagram correctly demonstrates the various forces acting on a ball moving horizontally with some speed?

Consider a 1000 w iron whose base plate is made of 0.5 cm thick aluminum alloy 2024-t6 (ρ = 2770 kg/m3 and cp = 875 j/kg°c). the base plate has a surface area of 0.03 m2. initially, the iron is in thermal equilibrium with the ambient air at 22°c. assuming 90% of the heat generated in the resistance wires is transferred to the plate, determine the minimum time needed for the plate temperature to reach 200°c.

A1000-kg car is moving at 30 m/s around a horizontal unbanked curve whose diameter is 0.20 km. what is the magnitude of the friction force required to keep the car from sliding?