The spreading out of waves after they pass through a narrow opening is?

Matter is needed to transfer thermal energy bya. conductionb. convectionc. radiation d. both a & b.

Aball is thrown horizontally from a cliff at 8m/s .in what direction is the ball moving 2s later?

An object dropped from cliff falls with a constant acceleration of 10 metre per second square find its speed of two seconds after it was dropped