The radius of Earth is 6.37 x 10° m. The average Earth-Sun distance is 1 496 x 1011 m. How many Earths would fit between Earth and the Sun if they are separated by their average distance? Use an order-of-magnitude calculation to estimate this
number. Then, determine an exact answer and express it in scientific notation with the correct number of significant digits.

Answer sample (c); // would be best because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the smallest;

You need to be more specific.  i really don't know what a "motion map" is.you can draw a graph of an object's position, distance, displacement, speed,velocity, or acceleration versus time, or you can draw a graph of the object's x-position versus its y-position and not give any information about time at all.if the graph presents position or displacement against time,  then constant velocity is a straight line . . i.e. a line that has  constant slope.if the graph shows speed against time, then constant velocityis a horizontal piece of line.if the graph shows acceleration against time, then constant  velocity is a piece of line that lies on the x-axis . . it's value is zero.