Skateboarding Physics: Min Speed, Optimal Ramp Angle & Displacement Vector

[kevin948]

Homework Statement

(Please check the attached file)

a)What is the minimum speed he requires to make it to the ramp?
b)What would be the best ramp angle so that the skateboarder lands as smoothly as possible?
c)What is the skateboarder’s displacement vector, average velocity vector, and average acceleration vector, between the moment the he leaves the ledge to the moment he reaches the other side?

Homework Equations

△y =Vi,y △t + ½ ay△t²

The Attempt at a Solution

I solved question A

-1 = -4.9△t²

0.45s

4m/0.45s = 8.8m/s

but I don't know how to solve question B and C

 

[Doc Al]

For B, how do you think the ramp angle should relate to his direction of motion? What is the skater's direction of motion?