Question

I need a formula to help understand how to get the answer?

Answer 1

From the table:

When time;

`t_1=0\text{ s}`

The position;

`x_1=20\text{ m}`

And when time,

`t_2=4\text{ s}`

The position;

`x_2=40\text{ m}`

The average velocity is given as,

`\begin{gathered} v_(av)=\frac{\text{ total displacement}}{\text{ total time taken}} \\ =(x_2-x_1)/(t_2-t_1) \end{gathered}`

Substituting all known values,

`\begin{gathered} v_(av)=\frac{(40\text{ m})-(20\text{ m})}{(4\text{ s})-(0\text{ s})} \\ =5\text{ m/s} \end{gathered}`

Therefore, the average velocity at t=4 s is 5 m/s.