Answer:
[tex]-4 m/s^2[/tex]
Explanation:
The acceleration of the bycicle is given by:
[tex]a=\frac{v-u}{t}[/tex]
where
v = 20 m/s is the final velocity of the bike
u = 40 m/s is the initial velocity
t = 5 s is the time interval
Substituting numbers, we find
[tex]a=\frac{20 m/s-40 m/s}{5s}=-4 m/s^2[/tex]
and the acceleration is negative, which means that the bycicle is slowing down.
