Question

the speed limit on some interstate highways is roughly 135 km/h. (a) what is this in meters per second? m/s enter a number. (b) how many miles per hour is this? mi/h

Explanation:

Step1: Convert km to m and h to s for part (a)

We know that 1 km = 1000 m and 1 h=3600 s.
To convert 135 km/h to m/s, we use the conversion factor:
\[135\frac{\text{km}}{\text{h}}\times\frac{1000\text{ m}}{1\text{ km}}\times\frac{1\text{ h}}{3600\text{ s}}=\frac{135\times1000}{3600}\text{ m/s}\]

Step2: Calculate the value for part (a)

\[ \frac{135\times1000}{3600}=\frac{135000}{3600} = 37.5\text{ m/s}\]

Step3: Convert km to miles for part (b)

We know that 1 km = 0.621371 miles.
To convert 135 km/h to mi/h, we use the conversion factor:
\[135\frac{\text{km}}{\text{h}}\times\frac{0.621371\text{ mi}}{1\text{ km}}=135\times0.621371\text{ mi/h}\]

Step4: Calculate the value for part (b)

\[135\times0.621371 = 83.885085\approx83.9\text{ mi/h}\]

Answer:

(a) 37.5
(b) 83.9