Question

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?

Answer 1

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.

Answer 2

Momentum p = 5.375 kgm/s

Step-by-step explanation:

Given

Density
`\rho = 1.29 kg/m^3`

Volume
`V = 1 m^3`

Velocity
`v = 15 km/h`

Solution

Mass = Density x volume

`m = \rho * V\\\\m = 1.29 * 1\\\\ m = 1.29 kg`

velocity

`v = 15 km/h\\\\v = (15)/(3.6) m/s\\\\v = 4.17 m/s`

Momentum = mass x velocity

`p = m * v\\\\p = 1.29 * 4.17\\\\p=5.375 kgm/s`