Chapter 3, Problem 4STP

To determine

To Choose: The correct option.

Answer to Problem 4STP

Option A: $4.2\text{s}$

Explanation of Solution

Given:

Acceleration of flowerpot (acceleration due to gravity), $a=9.8{\text{m/s}}^{\text{2}}$

Initial velocity of the flowerpot, $u=0$

Height of the balcony, $s=85\text{m}$

Formula Used:

Second equation of motion:

  $s=ut+\frac{1}{2}a{t}^2$

Where, s is the displacement, u is the initial velocity, t is the time and a is the acceleration.

Calculations:

Substitute the values and solve:

  $\begin{array}{l}s=ut+\frac{1}{2}a{t}^2\\ 85=0+\frac{1}{2}\left(9.8\right){\left(t\right)}^2\\ t=4.2\text{s}\end{array}$

Conclusion:

Thus, correct option is A.