Review. The bar of mass m in Figure P31.83 is pulled horizontally across parallel, frictionless rails by a massless string that passes over a light, frictionless pulley and is attached to a suspended object of mass M. The uniform upward magnetic field has a magnitude B, and the distance between the rails is ,. The only significant electrical resistance is the load resistor R shown connecting the rails at one end. Assuming the suspended object is released with the bar at rest at t 5 0, derive an expression that gives the bars horizontal speed as a function of time.

Physics 2 for Engineering Week 14 Beats 2 sound waves with slightly different frequencies Tbeat= T a b (T -Tb) and f beat= 1 / Tbeat= f a b Tbeatis time it takes to go from minimum to minimum or maximum to maximum Tbeat= nT =a(n-1) T b Doppler Effect f heard by observer depends on relative motion of the source with respect to the observer f’ = f (vsound+- v observer/ (vsound+- v source Depends on relative motion of source and observer Moving towards each other – higher frequency Moving away from each other – lower frequency f is frequency of sound, and f’ is frequency of sound heard by the observer Source at rest, observer moves towards f’ = f (v s