Question 62
There are two concentric circular tracks of radii 100 m and 102 m respectively. A runs on the inner track and goes once round the track in 1 minute 30-seconds, while B runs on the outer track in 1 minute 32 seconds. Whoruns faster?
Solution
Let speed of A and B is 'a' m/s and 'b' m/s respectively.
Circumference of inner track = $$2\pi r = 200\pi$$ m
Circumference of outer track = $$2\pi r = 204\pi$$ mNow,
$$a = \frac{200\pi}{90} = 2.22\pi$$ m/s (Approx)
$$b = \frac{204\pi}{92} = 2.21\pi$$ m/s (Approx)
Hence, A is faster than B.
