A. True
They are formed behind an obstacle when the wind blows the sand up to it.
An ideal gas differs from a real gas in that the molecules of an ideal gas have no attraction for one another.
An ideal gas is defined as one in which collisions between atoms or molecules are perfectly elastic and in which there are no inter-molecular attractive forces. A real gas on the other hand is a gas that does not behave as an ideal gas due to interactions between gas molecules. Particles in a real gas have a real volume since real gases are made up of molecules or atoms that typically take up some space even though they are extremely small.
<em><u>Question</u></em>
<em><u>What </u></em><em><u>does </u></em><em><u>it </u></em><em><u>mean </u></em><em><u>to </u></em><em><u>optimize</u></em><em><u> </u></em><em><u>a </u></em><em><u>solution?</u></em>
<em><u>To find out best possible solution for a given problem within the given constraint is generally termed as optimization</u></em>
<em><u>How </u></em><em><u>are </u></em><em><u>solution</u></em><em><u> </u></em><em><u>optimize</u></em><em><u> </u></em><em><u>?</u></em>
<em><u>To solve an optimization problem, begin by drawing a picture and introducing variables. Find an equation relating the variables. Find a function of one variable to describe the quantity that is to be minimized or maximized. Look for critical points to locate local extrema.</u></em>