Answer:
a) [tex]1.2\times 10^2\ N[/tex]
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
a = Acceleration
[tex]v=u+at\\\Rightarrow a=\frac{v-u}{t}\\\Rightarrow a=\frac{0-6}{4}\\\Rightarrow a=-1.5\ m/s^2[/tex]
The acceleration of the bicycle and rider is -1.5 m/s²
Force
[tex]F=ma\\\Rightarrow F=80\times -1.5\\\Rightarrow F=-120\ N=-1.2\times 10^2\ N[/tex]
The magnitude of the average force needed to bring the bicycle and its rider to a stop is [tex]1.2\times 10^2\ N[/tex]
