Physics Help – Easy

Ok these are introductory physics questions that for some reason I can’t get correct. 1) A position-time graph for a particle moving along the x axis is shown in the figure. The divisions along the horizontal axis represent 1.75 s and the divisions along the vertical axis represent 4.0 m.

-(b) Determine the instantaneous velocity at t = 7.00 s (where the tangent line touches the curve) by measuring the slope of the tangent line shown in the graph.
2)
A person walks first at a constant speed of 5.40 m/s along a straight line from point a to point b and then back along the line from b to a at a constant speed of 2.95 m/s.
(a) What is her average speed over the entire trip?
3) Find the instantaneous velocity of the particle described in the figure below at the following times.

(b) t = 2.5 s
Answer #1
This is just application of the corresponding formulas. What is it that you do wrong?