Question

How many A particle falling under gravity describes 80 ft in a certain second.How long does it take to describe the next 112 ft?

Answer 1

Explanation:

Let us consider the velocity of particle when it completes 80 ft is v 

and this velocity will be initial velocity for the 112 ft height. let us

consider it takes t time.

g = 32 ft/s^2

v^2 = u^2 + 2gh

v^2 = 0^2+ 2* 32* 80

v = √(64*80)

v = 8x4√(5)

v = 71.55 ft/s

now h = vt+0.5 x g x t^2

112 = 71.55t+0.5 x 32 x t^2

On solving 

t = -b ±√(b^2-4ac) / 2a

t = 1.2 sec

i hope it will help you

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