Can someone please help me with these

True or false when elements combine to form a mixture, the resulting chemical properties may be very different from those of the elements that make it.

An object moves from position +34m to the position -15m in 15 seconds. what is the total displacement? what is the total velocity?

Tafari worked one summer on a ship that set weather buoys in the ocean. he watched how one of the buoys moved in the water. describe which parts of the wave would cause the buoy to bob up and down. which wave property determined how fast the buoys bobbed in the water? he observed that when the wind blew harder, the ocean waves were larger, and the buoys moved away from the ship. what effect, if any, did the waves have on how far the buoys moved? explain your answer.