What is the rate at which work is done in lifting a 35-kilogram object vertically at a constant speed of 5 meters per second?
1) 1700 w
2) 340 w
3) 180 w
4) 7 w

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