Question
A race track is in the shape of a rectangle with length
of 22 metres and area of 2200 m2. A car takes 20 seconds to make one lap around the perimeter of this track. If the car and a person whose speed is 4 m/s, started moving at the same time along the perimeter of the track but in opposite directions, then find the distance between the car and the person, 3 seconds before they cross each other.Solution
Area of the track = length of track x breadth of track = 22 x breadth of track = 2200 So, breadth of track = 2200 ÷ 22 = 100 So, perimeter of the track = (22 + 100) x 2 = 244 metres So, speed of the car = (244/20) = 12.2 m/s Relative speed of the car with respect to the person = 12.2 + 4 = 16.2 m/s So, distance between the car and the person, 3 seconds before they cross each other = 16.2 x 3 = 48.6 metres
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