The equation is
s= d/t
In this case you would have to write it out as:
s= 20/5
Speed = 4
A mechanical wave is a wave that is an oscillation of matter, and therefore transfers energy through a medium. While waves can move over long distances, the movement of the medium of transmission—the material—is limited. Therefore, the oscillating material does not move far from its initial equilibrium position.
Heat = change in internal energy + Work done The internal energy of a system = heat added and mechanical work done by the system, i.e. U = Q + W rearranging the formula above, will give us: Q = deltaU + W
Q = U - W = 604 kJ - 43.0 kJ = 561,000 J would be the answer.