Answer:
B. +5.75 m/s
Explanation:
When there are two bodies, a and b, whose velocities measured by a third observer (in this case, the ground) are
and
respectively, the relative velocity of B with respect to A is given by:

Thus, the velocity of the girl relative to the lawnmower is:

It goes in the downward direction
You are currently converting Distance and Length units from Centimeters to Feet 321 Centimeters (cm) = 10.5315 Feet (ft) This is a hard one but see if this helps if not let me now and i can try again..
Primarily to survey and map the landscape of Mars for future missions. It also takes core samples and searches for water underground. This is important for many reasons, but most obviously for the upcoming missions to mars and the colonies that follow. Hope this helps?