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A ball falls vertically after being dropped.The ball falls a distance d metres in a time of t seconds.d is directly proportional to the square of tThe ball falls 20 metres in a time of 2 seconds.a)Find a formula for d in terms of t. |
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Answer» d is proportional to the square of tSo we can write: (1) . . d = K * t^2 . . where K is some constant. At the moment we don't know the value of this constant. But we do know that the ball has fallen 20 metres after 2 seconds. This info will give us the value of K. Substituting d=20 and t=2 into equation (1), we get 20 = K * 2^220 = K * 4K = 5 So, using the value 5 for K, equation (1) becomes: d = 5t^2 . . (d in metres, t in seconds) This is the formula for d in terms of t |
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