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15 votes
15 votes
A ball is launched upward at 26 ft/sec from a platform that is 12 feet high. When will the ball hit the ground

User Lsilva
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1 Answer

14 votes
14 votes

Answer:

9.4 seconds or 1 second

Explanation:

From;

h = ut ± 1/2gt^2

h = 12 feet

g = acceleration due to gravity = 10 m/s^2

u = 26 ft/sec

Since it is an upward motion g is negative

12 = 26t - 5t^2

Hence;

5t^2 - 26t + 12 = 0

Solving the quadratic equation

Considering that the time taken to go up is the same time taken to hit the ground again

t = 2(4.7) seconds or t = 2(0.5) seconds

t = 9.4 seconds or 1 second

User SeinopSys
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2.9k points