Questions: A car travels 4.0 km (E) and then 3.0 km (S). The total trip requires 15 min. The average velocity of the car for this trip is: 28 km / h 20 km / h 5 km / h 4.0 km / h 11 km / h

Solution Steps

The car travels \(4.0 \, \text{km}\) east and \(3.0 \, \text{km}\) south. To find the displacement, we use the Pythagorean theorem:

\[ \text{Displacement} = \sqrt{(4.0 \, \text{km})^2 + (3.0 \, \text{km})^2} = \sqrt{16 + 9} = \sqrt{25} = 5.0 \, \text{km} \]

The total time for the trip is 15 minutes. We need to convert this time into hours:

\[ \text{Time in hours} = \frac{15 \, \text{minutes}}{60 \, \text{minutes/hour}} = 0.25 \, \text{hours} \]

Average velocity is defined as the total displacement divided by the total time. Using the displacement and time calculated:

\[ \text{Average velocity} = \frac{5.0 \, \text{km}}{0.25 \, \text{hours}} = 20 \, \text{km/h} \]

Final Answer