Here's the question you clicked on:
nicolek9
i also do not understand 60 miles per hour to miles per second can you please explain too?
To answer that, let's answer an easier question first... If you are going 60 miles per hour, how many miles per minute are you going?
\[1[\text {min}]=60[\text{sec}]\quad\implies\quad\frac1{60}\frac{[\text {min}]}{[\text{sec}]}=1\]\[1[\text {hr}]=60[\text{min}]\quad\implies\quad \frac{1}{60}\frac{[\text{hr}]}{[\text{min}]}=1\] \[60 \frac{[\text{mi}]}{[\text{hr}]}=60 \frac{[\text{mi}]}{[\text{hr}]}\times1\times1\] \[\qquad\qquad= 60 \frac{[\text{mi}]}{[\text{hr}]}\times\frac{1}{60}\frac{[\text{hr}]}{[\text{min}]}\times\frac1{60}\frac{[\text {min}]}{[\text{sec}]}\] \[\qquad\qquad= \cancel{60} \frac{[\text{mi}]}{\cancel{[\text{hr}]}}\times\cancel{\frac{1}{60}}\frac{\cancel{[\text{hr}]}}{\cancel{\text{min}]}}\times\frac1{60}\frac{\cancel{[\text {min}]}}{[\text{sec}]}\] \[\qquad\qquad=\frac1{60}\frac{[\text{mi}]}{[\text{sec}]}\]
can you understand that ?