D.
50 mph - 30 mph= 20 mph net velocity
change.
20mph/3600 seconds/hour= .00555 MPS
.0055 miles per second
40 seconds to complete the change
.0055/40= .000138
B - speed and direction are combined in another quantity, called velocity. It can be thought of as its speed in a particular direction. Speed is the corresponding scalar quantity, because it does not have a direction.
Heat rises, and it is warmer at the equator, so I think warm air would rise at the equator and move towards the cooler poles.
<span>The Climate Friendly Farming Project was designed to provide funding for long term research into the sustainability and adaptability of agricultural systems(wheat, vegetables, and dairy systems) as increasing greenhouse gases
propagate and decline the efficiency of current agricultural practice.</span>
