A75-kg box rests on a horizontal surface. the coefficient of static friction between the box and the surface is 0.30, and the coefficient of kinetic friction is 0.20.
what horizontal force must be applied to the box to cause it to start sliding along the surface?

Which statement best describes the superposition principle? a.) if two in-phase waves arrive simultaneously at a point, their amplitudes add up b.) if two out-of-phase waves arrive simultaneously at a point, their amplitudes add up c.) if two in-phase waves arrive at a point one after another, their amplitudes add up d.) if two out-of-phase waves arrive at a point one after another, their amplitudes adds up