The Tacoma Narrows Suspension Bridge collapsed as a result of 40-mile-per-hour (64 km/h) wind conditions on the morning of November 7, 1940. A video of the collapse can be found here. Discuss physics principles that could have led to the collapse. Estimate the period and wavelength of the standing wave. (The full bridge length was around 1800 meters, but the longest span was 850 meters.) How could 40 mph winds cause such damage

4r-134a enters the condenser of a residential heat pump at 800 kpa and 50°c at a rate of 0.022 kg/s and leaves at 750 kpa subcooled by 3°c. the refrigerant enters the compressor at 200 kpa superheated by 4°c determine (a) the isentropic efficiency of the compressor, (b) the rate of heat supplied to the heated room, and (c) the cop of the heat pump. also, determine (d) the cop and rate of heat supplied to the heated room if this heat pump operated on the ideal vapor-compression cycle between the pressure limits of 200 and 800 kpa. (0.757, 4.37 kw, 5.12, 6.18, 3.91 kw)