Question

If a globe rotates through 150 degrees in 5 seconds, how many rotations does it make in 30 seconds?

Answer 1

Answer:

2.5 rotations in 30 seconds.

Step-by-step explanation:

Start with a proportion, to get the number of degrees in 30 seconds:

        (150 degrees / 5 seconds) = (’D’ degrees / 30 seconds).

Cross multiply the proportion:  (150 x 30) = 5 x D

                                                    4,500  =  5 x D

Divide each side by  5 :                  900 = D

The globe turns 900 degrees in 30 seconds.

How many rotations is that?

Each rotation is 360 degrees.

So 900 degrees is

                              (900 / 360) = 2.5 rotations in 30 seconds.