a) A 10.0 kg crate is resting on a 6.0-meter long horizontal beam with a mass of 5.0 kg and held in place by a wire at a 37-degree angle with respect to the board. Unfortunately, the pivot point is relatively weak, and if the vertical force exceeds 5.0 N, the pivot will break and the board will fall. How close can the crate be moved toward the wall before this happens

Point charges q1 = 51 µc and q2 = −27 µc are placed 1.0 m apart, with q2 on the right. what is the force (in n) on a third charge q3 = 19 µc placed midway between q1 and q2? (assume the positive direction is to the right. indicate the direction with the sign of your answer.)

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)

Acid precipitation chemically weathering a 5.0-kg limestone rock . which coukd be the result ?