Physics for Scientists and Engineers 3E by R. Knight, P1.27

Using the approximate conversion factors in Table 1.5, convert the following to SI units to English units without using your calculator.

a. 30 cm

b. 25 m/s

c. 5 km

d. 0.5 cm

Solution:

Part a

\displaystyle 30\:cm\approx \left(30\:cm\right)\left(\frac{4\:in}{10\:cm}\right)\approx 12\:in         ☚

Part b

\displaystyle 25\:m/s\approx \left(25\:m/s\right)\left(\frac{2\:mph}{1\:m/s}\right)\approx 50\:mph         ☚

Part c

\displaystyle 5\:km\approx \left(5\:km\right)\left(\frac{0.6\:mi}{1\:km}\right)\approx 3\:mi          ☚

Part d

\displaystyle 0.5\:cm\approx \left(0.5\:cm\right)\left(\frac{1/2\:in}{1\:cm}\right)\approx 0.3\:in          ☚