Question

an object thrown vertically upward reaches a height of 320 metre what was its initial velocity how long will the object take to come back to the earth assume G is equal to 10 metre per second square

Answer 1

it's easy initial velocity=2×10×320

Answer 2

height reached : 320m

initial velocity : ?

acceleration (g) : 10m/s²

final velocity : 0m/s

therefore , u:

2as = v² -u²

2×10×320 = 0² - u²

6400 = 0-u²

6400 = -u²

√6400 = -u

-80 m\s= u

thus, t =

v=u +at

0 = -80 + 10×t

0+80 = 10t

80/10 = t

8s =t

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