Question

Suppose you increase your walking speed from 4 m/s to 15 m/s in a period of 1 s. What is your acceleration?

Answer 1

Answer:

The acceleration is: $11\,\frac{m}{s^2}$

Explanation:

Recall that acceleration is defined as the change of velocity over the time it took to produce this change. This is expressed mathematically as:

$a=\frac{v_f-v_i}{t_f-t_i}$

with $v_i$ being the initial velocity of the person (in our case 4 m/s);

$v_f$ being his final velocity (in our case 15 m/s);  

and the difference $t_f-t_i$ the time the change in velocity took (in our case 1 second).

Therefore in our example, the person's acceleration is:  

$a=\frac{v_f-v_i}{t_f-t_i}\\a=\frac{15-4}{1}\,\frac{m}{s^2} \\a=11\,\frac{m}{s^2}$