To determine the centroid of the object first moment of area is used.
To predict the resistance of a shape to bending and deflection which are directly proportional, second moment of area is used.
It is the mathematical and conceptual framework for contemporary Elementary practical physicas. if that make sense to you.
Answer:
t=1.623 sec
Explanation:
The distance traveled before the echo is had is:

Given the speed of sound as v=345m/s, we use the speed equation to solve for t:

Hence, it takes 1.623 seconds to hear the echo.
<span>The answer is C: water is drawn up a straw by cohesion and adhesion. Water molecules stick to one another and the walls of the straw, just like in a capillary.
Cohesion is the attractive force between like materials (between water
molecules).
Adhesion is the attractive force between twounlike materials (such as between
water and a solid container).
Capillary action is the tendency of a liquid to rise innarrow tubes or small openings as a result of adhesion and cohesion.
The liquid water molecules bind to the straw—a process known as adhesion. In the narrow space of the straw, the interaction of cohesion and adhesion causes theliquid to be drawn upward in the straw.</span>
Answer:
4 km/hr
Explanation:
suppose 's' is Diane's speed with no current.
't' represents time in hrs.
Using the formula:
Distance = speed 's' x time 't'
-> when she swims against the current, equation will be,
5= (s-2)t
t= 5/(s-2)
->when she was swimming with the current, equation is,
15= (s+2) t
t= 15/(s+2)
equating eq(1) and (2)
5/(s-2) = 15/(s+2)
5s + 10 = 15s - 30
40= 10s
s= 40/10
s=4
Therefore, if there were no current, her speed is 4km/hr