Question 3
a) to find the time taken for the halfway distance of the circular track we simply have to find the distance of the full circular track then divide it by two. As we know that distance travelled by car in one full orbit or revolution is = circumference of the cirlce = 2 * Pi * r
So for the halfway it must be the half of that equation so it becomes like this
Circumference of half circle = Pi * r
Find r by dividing the diameter by two . Then substitute its value in the circumference equation, and you get the distance.
Then use this equation to solve for the time needen
time = distance / speed
b) Not sure about this part ::
Average velocity = Displacement / Time taken
I think that the displacement here is basiclly the distance traveled that we have found in part a and the time taken also found in part a so it may be the of speed which is 20 m/s . Please Check the answer.