Problem 2-62 - Distance and speed - Part 5 (a)

A truck travels at \(80\; km/h\) for \(30\; min\), then at \(60\; km/h\) for \(1.5 \;hr.\) Assuming 2 significant digits in the given numbers, calculate the truck's
(a) total distance traveled, and
(b) average speed.

Accumulated Solution

\(\text{speed} = \frac{d}{\Delta t} \\ d = \text{(speed)} \Delta t \\ d_1 = 40\; km \\ d_2 = 90\; km\)

Correct!

\(d_2 = (60\; km/hr)(1.5\; hr) = 90\; km\)

The total distance is (re-read the question):

(A)   \(130\; km\)

(B)   \(1.3 \times 10^2\; km\)

(C)   \(1.30 \times 10^2\; km\)