pre calc question

Question

The formula v=√2.6r models the maximum safe speed, v, in miles per hour, at which a car can travel on a curved road with radius of curvature r, in feet. A highway crew measures the radius of curvature at an exit ramp on a highway as 610 feet. What is the maximum safe speed?

For this problem, round your answer DOWN to the nearest whole number. (Think: Why is this type of rounding appropriate for this scenario?)

max safe speed = 

Answer 1

This is a simple multiplication problem hidden inside a square root, starting on the inside going out (2.6 * 610) = 1586. We then take the square root of 1586 which can actually be written in two ways. The first using the square root sign √1586 or the far superior way in my opinion (1586)^1/2

These both equal 39.824 mph and applying the rounding rule that ensures safety we get a final answer of 39 mph.