A converging lens with the same curvature on both faces and a focal length of 25 cm is to be made from crown glass having a refractive index of 1.52. What radius of curvature is required for each face

Talia is manufacturing rolls of wire for hanging pictures. she needs a material that is so that it can easily be pulled into wire without breaking.

Air enters a gas turbine with two stages of compression and two stages of expansion at 100 kpa and 17°c. this system uses a regenerator as well as reheating and intercooling – the intercooler returns the air to the inlet temperature. the pressure ratio across each compressor is 4 ; 300 kj/kg of heat are added to the air in each combustion chamber; and the regenerator operates perfectly while increasing the temperature of the cold air by 20°c. determine the system’s thermal efficiency. assume isentropic operations for all compressor and the turbine stages and use constant specific heats at room temperature. (0.378)

According to the image below, which season is about to begin in the southern hemisphere? a. summer b. autumn c. winter d. spring