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A car is travelling around a road. it passes point A at a constant speed of vms-1 and drives for t seconds at this speed. it then accelerates at a constant rate for 6 until it reaches speed of 2v ms-1. maintaining this speed, it arrives at point B after a further 2t seconds. the total distance travelled between A and B was 528m and the average speed was 20ms. find v and t​.

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Final answer:

To find the values of v and t, we can use the given information to set up two equations. The first equation relates the distances traveled during each part of the journey, while the second equation relates the average speed to the total distance and time. Solving these equations simultaneously will give us the values of v and t.

Step-by-step explanation:

To solve this problem, we first need to understand the given information:

  • The car travels at a constant speed of v m/s for t seconds.
  • Then, it accelerates at a constant rate until it reaches a speed of 2v m/s.
  • Finally, it maintains this speed and arrives at point B after an additional 2t seconds.
  • The total distance traveled between A and B is 528 m.
  • The average speed is 20 m/s.

We can start by finding the distance traveled during the first part of the journey, where the car is traveling at a constant speed. The distance is given by: d = v * t.

We can then find the distance traveled during the second part of the journey, where the car is accelerating. We know that the car accelerates for 6 seconds until it reaches a speed of 2v m/s. Using the equation of motion, we can find the distance traveled during acceleration: d = (1/2) * a * t^2, where a is the acceleration and t is the time taken for acceleration.

Finally, we can find the distance traveled during the third part of the journey, where the car maintains a speed of 2v m/s for 2t seconds. Again, we can use the equation of motion to find the distance: d = 2v * 2t.

The total distance traveled between A and B is the sum of these three distances: 528 = v * t + (1/2) * a * t^2 + 4v * t. Simplifying this equation, we have:

528 = t * (v + 4v + (1/2) * a * t)

528 = t * (5v + (1/2) * a * t)

Using the given information that the average speed is 20 m/s, we can write another equation: average speed = total distance / total time. Substituting the given values, we have 20 = 528 / (t + 6 + 2t).

By solving these two equations simultaneously, we can find the values of v and t.

User Nimit Dudani
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