Respuesta :
Given data
*The speed of the cyclist is u = 7 m/s
*The given distance is s = 11 m
*The given time is T = 0.400 s
(a)
The formula for the acceleration of the cyclist to just avoid the collision is given by the equation of motion as
[tex]\begin{gathered} v^2=u^2+2as \\ a=\frac{v^2-u^2}{2s} \end{gathered}[/tex]*Here v = 0 m/s is the final speed of the cyclist
Substitute the known values in the above expression as
[tex]\begin{gathered} a=\frac{(0)^2-(7)^2}{2\times11} \\ =-2.22m/s^2 \end{gathered}[/tex]Hence, the acceleration of the cyclist to avoid the collision is a = -2.22 m/s^2
(b)
The formula for the time taken to cross the distance of 11 m is given by the equation of motion
[tex]s=ut+\frac{1}{2}at^2[/tex]Substitute the known values in the above expression as
[tex]undefined[/tex]