If somebody swim to the right for 30 meters then swims to left for 15 meters and then swims back to the right for 50 meters whats is the person displacement

Henry, whose mass is 95 kg, stands on a bathroom scale in an elevator. the scale reads 830 n for the first 2.4 s after the elevator starts moving, then 930 n for the next 2.4 s. part a what is the elevator's speed 4.8 s after starting? express your answer with the appropriate units.