Chapter 4, Problem 38A

On a distant planet a freely-falling object has an acceleration of $20{\text{m/s}}^2$. Calculate the speed an object dropped from rest on this distant planet acquires in 1.5 s.

To determine

The speed acquired by an object in $1.5\text{s}$ when it is dropped from rest.

Answer to Problem 38A

  $30\text{m/s}$

Explanation of Solution

Given:

The acceleration of a free-falling object on a distant planet, $a=20{\text{m/s}}^{\text{2}}$ .

Formula used:

The instantaneous speed in free fall at a timet is given by,

  $v=at$

where, $a=$ acceleration of free fall

Calculation:

Using the above-mentioned formula and given value, the speed acquired in $1.5\text{s}$ will be,

  $\begin{array}{c}v=\left(20\right)\left(1.5\right)\\ =30\text{m/s}\end{array}$

Conclusion:

Hence, the acquired speed in $1.5\text{}\text{s}$ is $30\text{m/s}$ .