## Question:

A power lawn mower hovers very close over the ground. This is done by drawing air in at speed ${ v }_{ A }$ through an intake unit A, which has cross-sectional area ${ A }_{ A }$ and then discharging it at the ground, B, where the cross-sectional area is ${ A }_{ B }$. If air at A is subjected only to atmospheric pressure, determine the air pressure which the lawn mower exerts on the ground when the weight of the mower is freely supported and no load is placed on the handle. The mower has mass M with center of mass at G. Assume that air has a constant density of ${ ρ }_{ a }$. Given: ${ v }_{ A }$ = 6 m/s , ${ A }_{ A }$ = 0.25 ${ m }^{ 2 }$, ${ A }_{ B }$ = 0.35 ${ m }^{ 2 }$, M = 15 kg , ${ ρ }_{ a }$ = 1.22 kg/${ m }^{ 3 }$