science
Grade-9
Easy
Question
A biker takes 2.5 laps of a circular track of radius 7 m. Her distance and displacement are ___ m and ___ m respectively.
Hint:
110 m, 14 m
The correct answer is: 110,14
Circumference of the circular track = 2πr, r = radius of the circular track
Thus, circumference = 2x (22/7) x 7 = 44 m
Therefore, the distance covered by the biker in 2.5 laps = 44 x 2.5 = 110 m
At the end of 2.5 laps, she would reach a point which is diametrically opposite to her initial point.
Therefore, her displacement = diameter of the circular track = 7 + 7 = 14 m
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