Taking the density of air to be 1.29 kg/m^3, what is the magnitude of the linear momentum of a cubic meter of air moving with the following wind speed of 15 km/h?

Density = mass divided by volume. So, the mass = density times volume. mass = 1.29 x 1 kglinear momentum is defined as mass times velocityso the linear momentum of a cubic metre at 15,000 m per hour would be 1.29 x 15km/h. The units would be kg km/h, which are not the SI units. These are kg m/s. To get to them the speed has to be converted into metres per second.