A vehicle travelling at 90 km/h decelerates to 50 km/h in 9 seconds. How far does it travel in this duration?

To determine the distance traveled by the vehicle during the deceleration from 90 km/h to 50 km/h over a period of 9 seconds, we can use the formula for average speed when the initial and final speeds are known.

First, we convert the speeds from km/h to m/s:

• The initial speed (90 km/h) is converted by multiplying by (1000 m / 1 km) and dividing by (3600 s / 1 h), resulting in:

[

90 , \text{km/h} \times \frac{1000}{3600} = 25 , \text{m/s}

]

• The final speed (50 km/h) converts to:

[

50 , \text{km/h} \times \frac{1000}{3600} = \approx 13.89 , \text{m/s}

]

Next, calculate the average speed during this deceleration:

[

\text{Average Speed} = \frac{\text{Initial Speed} + \text{Final Speed}}{2} = \frac{25 , \text{m/s} + 13.89 \