Question

answer these questions

Answer 1

Are you really asking us to answer 22 questions in one single post?
This is not the correct method to ask.
Ask one question in each post.

91.
x = 6t
ux = dx/dt = 6
At t = 0
ux = 6 m/s

y = 8t - 5t²
uy = dy/dt = 8 - 10t
At t = 0
uy = 8 m/s

u = sqrt(ux² + uy²)
u = sqrt(6² + 8²)
u = 10 m/s
(2) is the correct option.