Find the speed S by using radical equations There are two word problems that I cannot write as radical equations.
1.A formula that is used for finding the speed s, in mph, that a car was going from the length L, in feet, of its skid marks can be written as s=2 square root of 5L. In 1964, a jet powered car left skid marks nearly 6 miles long. According to the formula, how fast was the car going? (5280 feet= 1 mile)
2.A ship's speed s (in knots) varies based on the following equation s= 6.5 7th root p where p is the horsepower generated by the engine. If a ship is traveling at a speed of 25 knots, how much horsepower was the engine generating?
Thanks for your help.

For the first question, we can see that the speed if a function of the length of the skid mark. Therefore,
$$
S = f(L)
$$
We also know that the relation between $ S $ and $ L $ is that $ S $ is $2$ times square root of $5L$ 
$$
S = 2 \times \sqrt{5L}
$$
Similarly, for the next question,
$$
S = 6.75 \times \sqrt[7]{P}
$$
