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Speed, distance, time question? please help

A car travels from A at 2ms-2 until it reaches a speed of 40ms-1. The car then continues at 40ms-1 for 120 seconds. The car then decelerates uniformly for at 3ms-2 until it reaches B.

What is the total time of the journey, and what is the total distance?
Original post by Worms
A car travels from A at 2ms-2 until it reaches a speed of 40ms-1. The car then continues at 40ms-1 for 120 seconds. The car then decelerates uniformly for at 3ms-2 until it reaches B.

What is the total time of the journey, and what is the total distance?


There are three separate sections in the journey:

A) the car is accelerating for a time.
B) the car is moving at a constant speed for 120s
C) the car is decelerating for a time.

The total time is A+B+C

Do the same thing for distance by separating into three parts.
You will need to choose an appropriate SUVAT equation for each part.
Draw a graph and then find the area under the graph.

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natninja
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Original post by Worms
A car travels from A at 2ms-2 until it reaches a speed of 40ms-1. The car then continues at 40ms-1 for 120 seconds. The car then decelerates uniformly for at 3ms-2 until it reaches B.

What is the total time of the journey, and what is the total distance?


assuming it stops at B

to find the time use suvat for each part of the journey. Then for the distance you can use suvat again or find the area under a distance time graph.
SUVAT isn't needed for the middle section, as this is just uniform velocity. It's just s=vt

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