Michael is floating in a hot air balloon 200 feet above the ground. He tosses out a coin with an initial velocity of 20 feet per second. How long until the coin will hit the ground? Use s = -16t^2 + v0t + s0. Round your answer to two decimal places.
Thank you!
How long until the coin will hit the ground?
2019-03-20 1:08 am
回答 (4)
2019-03-20 1:56 am
✔ 最佳答案
Take all upward quantities as positive. Hence,vₒ = 20 ft/s and sₒ = 200 ft
s = -16t² + 20t + 200
When the coin reaches the ground, s = 0
-16t² + 20t + 200 = 0
4t² - 5t - 50 = 0
t = [5 ± √(5² + 4*4*50)] / (2*4)
t = 4.22 or t = -2.97 (rejected)
Time taken = 4.22 s
2019-03-20 1:20 am
"20 feet per second" is not a velocity. If that is supposed to be upward, then we solve -16t^2 + 20t + 200 = 0
2019-03-20 1:35 am
The toss is downward.
-16t² - 20t + 200= 0
Solve using the quadratic formula.
t ≈ 2.9653516540863 s
-16t² - 20t + 200= 0
Solve using the quadratic formula.
t ≈ 2.9653516540863 s
2019-03-20 1:14 am
initial velocity in what direction? up? down? to the side? at what angle?
收錄日期: 2021-05-01 22:31:46
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