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Question
A bus decreases its speed from 80 km h−1 to 60 km h−1 in 5 s. Find the acceleration of the bus.
Solution
Initial velocity = 80km/h
= 80 × 100060 × 60
= 22.22 m/s
Time = 5s
Final velocity v = 60 km/h
= 60 × 100060 × 60
= 16.66 m/s
Acceleration = `"Change in velocity"/"Time taken"`
= `"(Final velocity - Initial velocity)"/"Time taken"`
= `(16.66-22.22 )/5`
= -1.11ms-2
Hence, acceleration of the bus = -1.11ms-2
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