Average speed for round trip with different speeds

[ella_101]

“if a cyclist travels at an average speed of 3m/s-1 and turns home at an average speed of 9m/s than what is the average speed of the whole journey?”


do I need an equation to work this out?

And please show how you got your answer.


Thanks

 

[lylos]

Try using the equations:

$$\bar{speed} = \frac{\Delta X}{\Delta t}$$
$$X = V_0{}t + at$$

Also, try using different values for X.