an athlete complets one round of a cricular track of diameter 400 m in 80 second. what will be the distance covered and the displacement at the and of 6 minute 40 second.
Answers
Answer:
Circumference of the track = Diameter×π = 400π m.
Total time taken = 2 min 20s = 140 s. Time taken for 1 round = 40 s. Number of rounds = 140 ÷ 40 = 3.5
This means having completed 3 and a half round the athlete is at a point diametrically opposite to his starting point. So, the magnitude of the displacement vector is 400m.
Distance travelled in 140s = 3.5×Circumference = 3.5 × 400π m = 1400π m = 4398.2297m approximately
Now, the difference between the two results, Mr Verma's and mine = (4400 - 4398.2297)m = 1.7703m.
We cannot ignore this difference of nearly 1.77meter, if the calculations really matter to anything in real life. At the same time, students should not bother to find a better result with a better π, specifically when calculator is NOT allowed.
π in Exam Hall 22/7,
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