i) x is the distance from the origin up the slope. So as it is rolled up the distance will increase and as we know by logic, it will roll down again right? Now there are different ways of doing this:
X Method:
Look at the maximum of the parabola. The x-value will be the maximum x value of the parabola.
Velocity Method:
At the moment when it begins to roll back what is the speed? You can differentiate in terms of t to find velocity easily. But then would have to sub in the time into x again...
ii) So if you did the velocity method, would have saved u some time. Now let x=0 (when it reaches the base again) and find the time. Sub the time into velocity. (Find velocity by differentiating x in terms of t).
iii)If you look carefully you would have found it in ii)
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