Speed of object

1 foot = 12 inches
1 inch = 2.54 cm
100 cm = 1 meter

The speed of an object is 32 feet per second. Which of the following computations gives the speed of the object in meters per second?

32(1/12)(2.54)

32(12)(2.54) (1/100)

32 (12)(2.54)(100)


can i do ft/sec in/ft cm/ in and m/ cm? Then I cancel out?

If you carry the units, rather than ignore them and hope, it is all quite clear.

\(\displaystyle 32 \frac{ft}{sec}\cdot \frac{12\;in}{ft}\cdot\frac{2.54\;cm}{in}\cdot\frac{m}{100\;cm}\)

Thanks. So what i did was cancel the ft (ft under 12 in) and in (in under 2.54 cm) to get 32(12) (2.54) (1/100) ?

You're still underestimating the power of the units. I object that they do not appear in your final expression. Other than that, I think you have it.

I like to do ft/sec into km/hour, just as a refreshing exercise.