13)
there are 2π radians in 1 revolution, and there are 60 seconds in 1 minute, so keeping that in mind, then,

14)


15)
what is the radians per seconds "w" in revolutions per minute? just another conversion like in 13)
The easy way to think about this is what number comes between 5 and 7? The answer is 6 (but we have to consider that it's negative in this case.) So the answer is -6 Another way to look at it is with a number line (not to "Which number is greater than -7 and less than -5"? scale.)<===(-7)==(-6)==(-5)==(-3)==(-2)==(-1)==(0)==(1)==>Notice how -6 comes between the two numbers. -6 is larger than -7 (it's "less negative" -- "Which number is greater than -7 and less than -5"? closer to zero) -6 is less than -5 (it's "more negative" -- further away from zero)