Question

a cyclist is travelling at 20 m/s she applies brakes so that she does not collide with a wall 18m away what retardation must she have​

Answer 1

Answer:

She will collide with wall.

Explanation:

The speed is too high. 20 m/s speed vs 18m, 20 m/s wins.

Answer 2

Answer:

cyclist is travelling at 20m/s so

u(initial velocity)= 20m/s

she applies brakes so the final velocity is 0m/s

v=0 m/s

distance(s) =18m

putting the values in the 3rd equation of motion (v^2= u^2+ 2as)

(0)^2= 20^2 + 2×a×18

0=400+36a

-400=36a

-400÷36=a

-11.111=a

so retardation= 11.111

Hope it helped!!