What conclusion can be drawn from the statement that an element has high electron affinity, high electronegativity, and a high ionization energy?
a) the element is most likely from group 1a or 2a and in period 1 or 2.
b) the element is most likely from group 2a or 3a and in period 6 or 7.
c) the element is most likely from group 4a or 5a and in period 4 or 5.
d) the element is most likely from group 6a or 7a and in period 2 or 3.

The ratio of lift to drag l/d for a wing or airfoil is an important aerodynamic parameter, indeed, it is a direct measure of the aerodynamic efficiency of the wing. if a wing is pitched through a range of angle of attack, l/d first increases, then goes through a maximum, and then decreases. consider an infinite wing with an naca 2412 airfoil. estimate the maximum value of l/d. assume that the reynolds number is 9x10^6.

Consider a file currently consisting of 200 blocks. assume that the file control block (and the index block in the case of indexed allocation) is already in memory. calculate how many disk i/o operations are required for contiguous, linked, and indexed (single-level) allocation strategies, for each of the conditions listed below. in the contiguous-allocation case, assume that there is not room to grow at the beginning but there is room to grow at the end. also assume that the block information to be added is stored in memory.

What is the magnitude of the gravitational force acting on the earth due to the sun?