Question

Help with homework not graded I learn best by watching you do problem Option D = 3.19 s

Answer 1

Given data:

* The height of the stone is h = 50 m.

* The initial horizontal speed of the stone is v = 4 m/s.

Solution:

By the kinematics equation along the vertical direction, the time taken by the stone to reach the ground is,

`h=ut+(1)/(2)gt^2`

where u is the initial vertical speed of the stone,

The initial vertical velocity of the stone is zero, thus,

`h=(1)/(2)gt^2`

where g is the acceleration due to gravity,

Substituting the known values,

`\begin{gathered} 50=(1)/(2)*9.8* t^2 \\ t^2=(2*50)/(9.8) \\ t^2=10.2 \\ t=\pm3.19\text{ s} \end{gathered}`

Neglecting the negative value of time,

Thus, the time taken by the stone to reach the ground is 3.19 s.

Hence, option D is the correct answer.