Respuesta :

Answer:

The average rate of speed of the model airplane, per second is 18 feet.

Step-by-step explanation:

Given:

It took the model airplane 5 seconds to go 90 feet.

Now, to find the average rate of speed in feet per second.

So, in 5 seconds the airplane go to = 90 feet.

In 1 second the airplane go to = 90 ÷ 5 feet.

Therefore, by dividing 90 feet by 5 seconds we get = 18 feet.

Thus, the average rate of speed of the model airplane, per second is 18 feet.