Answer:
a)
Now we can replace the velocity for t=1.75 s
For t = 3.0 s we have:
b)
And we can find the positions for the two times required like this:
And now we can replace and we got:
Explanation:
The particle position is given by:
Part a
In order to find the velocity we need to take the first derivate for the position function like this:
Now we can replace the velocity for t=1.75 s
For t = 3.0 s we have:
Part b
For this case we can find the average velocity with the following formula:
And we can find the positions for the two times required like this:
And now we can replace and we got: