Question

8. What would the shape of the graph be if the speed of the object decreased from 50.0 km/hr at 20 s to 30 km/hr at 40 s?9. What is the acceleration in Problem 8?

Answer 1

We will have the following:

8. The graph will be the following:

9. The acceleration of part 8 will be determined as follows:

First, we determine the equivalency of the velocities, that is

`\begin{gathered} (50km)/(h)\ast(1000m)/(1km)\ast(1h)/(3600s)=(125)/(9)m/s \\ \\ (30km)/(h)\ast(1000m)/(1km)\ast(1h)/(3600s)=(25)/(3)m/s \end{gathered}`

Then, the acceleration will be:

`a=\frac{(25/3\text{ }m/s)-(125/9\text{ }m/s)}{40s-20s}\Rightarrow a=-(5)/(18)m/s^2`

So, the acceleration was of -5/18 m/s^2.