Chapter 4, Problem 36A

Calculate the speed (in m/s) of a skateboarder who accelerates from rest for 3 seconds down a ramp at an acceleration of $5m/s^2$.

Velocity acquired in free fall, from rest: $v=gt$

To determine

Speed of skateboarder.

Answer to Problem 36A

  $v=15\text{m/s}$

Explanation of Solution

Given:

Acceleration from the rest, $a=5{\text{m/s}}^2$

Time, $t=3\text{s}$

Formula Used:

From rest position,

Instantaneous speed = acceleration × time

  $v=at$

Calculation:

Putting the given values in above relation,

  $\begin{array}{l}v=5\times 3\\ =15\text{m/s}\end{array}$

Conclusion:

Therefore, the speed of skateboarder is $v=15\text{m/s}$