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bleedblue1234
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this is the full question:
An elevator ascends with an upward acceleration of 4.0ft/s^2. At the instant its upward speed is 8.0ft/s, a loose bolt drops from the ceiling of the elevator 9.0 ft from the floor.
Calculate (a) the time of flight of the bolt from the ceiling to the floor
(b) the distance it has fallen relative to the elevator shaft.
Answer: (a) 0.71 (b) 2.3 ft
Here I will solve (good practice for AP physics anyways)
So first let's do the time from dropping to the time where it returns to the original drop height...
first conversions:
8.0ft = 2.4384 meters
9.0ft= 2.7432 meters
so just do this
-2.7432 = -2.4384t + 1/2(-9.80)t^2
so
0 = (-4.9)t^2 + (-2.4384)t + 2.7432
so use quadratic formula
t = (2.4384 + sqrt(-2.4384^2 * 4(-4.9)(2.7432))) / (2*-4.9)
so i had t=.540 s
An elevator ascends with an upward acceleration of 4.0ft/s^2. At the instant its upward speed is 8.0ft/s, a loose bolt drops from the ceiling of the elevator 9.0 ft from the floor.
Calculate (a) the time of flight of the bolt from the ceiling to the floor
(b) the distance it has fallen relative to the elevator shaft.
Answer: (a) 0.71 (b) 2.3 ft
Here I will solve (good practice for AP physics anyways)
So first let's do the time from dropping to the time where it returns to the original drop height...
first conversions:
8.0ft = 2.4384 meters
9.0ft= 2.7432 meters
so just do this
-2.7432 = -2.4384t + 1/2(-9.80)t^2
so
0 = (-4.9)t^2 + (-2.4384)t + 2.7432
so use quadratic formula
t = (2.4384 + sqrt(-2.4384^2 * 4(-4.9)(2.7432))) / (2*-4.9)
so i had t=.540 s
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