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Question
A camera is accidentally knocked off an edge of a cliff 400 ft high. The camera falls a distance of s = 16t2 in t seconds. What is the average velocity with which the camera falls during the last 2 seconds?
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Solution
In 5 sec camera falls 400 ft ......(given)
∴ Average velocity in 2 sec
= `("s"(5) - "s"(3))/(5 - 3)`
= `(16(5^2) - 16(^2))/2`
= `(400 - 144)/2`
= `256/2`
= 128 ft/sec
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