Question

If Alexandria drives her car 750 meters in 25 seconds, then goes an additional 980 meters in 35 seconds. What is the average speed of Alexandria's car? (Show your work)

a) 45 m/s

b) 50 m/s

c) 55 m/s

d) 60 m/s

Answer 1

The average speed of Alexandria's car is c) 55 m/s

Step-by-step explanation:

To find the average speed, we can use the formula:
`\[ \text{Average Speed} = \frac{\text{Total Distance}}{\text{Total Time}} \]`

For the first part of the journey, Alexandria drove 750 meters in 25 seconds. Therefore, her speed during this part is
`\[ \text{Speed}_1 = \frac{750 \, \text{m}}{25 \, \text{s}} = 30 \, \text{m/s}`

For the second part, she covered an additional 980 meters in 35 seconds. The speed for this part is
`\[ \text{Speed}_2 = \frac{980 \, \text{m}}{35 \, \text{s}} = 28 \, \text{m/s} \]`

Now, we can find the total distance and total time for the entire journey:

`\[ \text{Total Distance} = 750 \, \text{m} + 980 \, \text{m} = 1730 \, \text{m} \]`

`\[ \text{Total Time} = 25 \, \text{s} + 35 \, \text{s} = 60 \, \text{s} \]`

Now, plug these values into the average speed formula:

`\[ \text{Average Speed} = \frac{1730 \, \text{m}}{60 \, \text{s}} = 28.83 \, \text{m/s} \]`

Rounding to the nearest whole number, the average speed of Alexandria's car is
`\( \approx 29 \, \text{m/s} \)`, which is closest to option (c) 55 m/s.