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A camera is accidentally knocked off an edge of a cliff 400 ft high. The camera falls a distance of s=16t^2 in t seconds. (i) How long does the camera fall before it hits the ground? (ii) What is the average velocity with which the camera falls during the last 2 seconds? |
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Answer» Answer: 5 secs 128ft/sec Step-by-step EXPLANATION: The camera falls a distance of s=16t^2 in t seconds S = 400 ft time Taken to reach ground => 400 = 16 * t² => t² = 25 => t = 5 sec Camera fall for 5 sec before it hits the ground in 5 sec camera fall 400 ft now 2 sec before that is 3 sec Camera has fallen for = 16 * 3² = 144 ft Distance covered in last 2 sec = 400 - 144 = 256 ft average velocity in last 2 sec = 256/2 = 128ft/sec |
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