Question

Find the final velocity of the ball that is dropped from the second floor if the ball takes 18 seconds before hitting the ground. The acceleration due to gravity is g = 9.80 m.s-2.​

Answer 1

$\huge{\underline{\underbrace{\mathcal\color{gold}{Answer}}}}$

Given,

Initial velocity, (vi)= 0 m.s-1

Final velocity,( vf )= ?

Acceleration due to gravity = a = g = 9.80 m.s-2

Time interval, t = 18 s

∴ From the definition, acceleration is given as:

$\boxed{\bold{\blue{a=\dfrac{v_{f}-v_{i}}{t} }}  }$ 

Rearranging the formula,

• vf=vi + at
• vf= 0+(9.80×18)
• vf=176.4 m.s-1

$\therefore$ The final velocity of the ball is 176.4 m.s-1.