Aformer student of mechanics wishes to weigh himself but has access only to a scale a with capacity limited to 120 lbs and a small 20-lb spring dynamometer
b. with the rig shown he discovers that when he exerts a pull on the rope so that b registers 17 lb, the scale a reads 94 lb. what is his correct weight?

two charges are fixed in place on the x-axis as shown. the charge at x = 0 is negative and has magnitude q = 2 μcoulombs (1 μcoulomb = 10-6 coulombs). the charge at x = d, (d = +12 cm), is positive and has magnitude q = 4 μcoulombs. find a point x = xo along the x-axis at which the electric field is zero.

the duration of a photographic flash is related to an rc time constant, which is 0.100 μs for a certain camera.