A > Is the correct answer :)
Answer:
The answer is 1.87nm/s.
Explanation:
The
water loss must be replaced by
of sap. 110g of sap corresponds to a volume of

thus rate of sap replacement is

The volume of sap in the vessel of length
is
,
where
is the cross sectional area of the vessel.
For 2000 such vessels, the volume is

taking the derivative of both sides we get:

on the left-hand-side
is the velocity
of the sap, and on right-hand-side
; therefore,

and since the cross-sectional area is
;
therefore,

solving for
we get:


which is the upward speed of the sap in each vessel.
Answer:
160 m
Explanation:
The intensity, I, of the sound is inversely proportional to the square of the distance, r, from the source.

Hence,


From the question,
is half of 



<span>Viscosity, the more a fluid resists flow, the more viscous the flow. For example, honey is a very viscous fluid, while water is not as viscous. Hope this helps(:</span>