The metric system is based on powers of 10 so it is much easier to convert units, often just by moving the decimal point.
Sound waves are longitudinal waves that is, are transmitted in the same direction of oscillation of the particles in the medium. Electromagnetic waves are transverse ie, the electric and magnetic fields, which are perpendicular to each other, oscillate perpendicularly to the direction of wave propagation.
Is it multiple choice or do you just answer
Q = mcΔθ
67.5 = m x 0.45 x (28.5 - 21.5)
M = 67.5 / 3.15
= 21.4 g
