3. a bike rider accelerates uniformly at 2.0 m/s2 for 10.0
s. if the rider starts from rest, calculate the distance
traveled in the fourth second.
(i. e. between t = 3 s and t = 4 s).

16 m

Explanation:

Since this situation is about constanta acceleration, we can use the following equations:

   (1)

(2)

Where:

is the bike rider's final velocity

is the bike rider's initial velocity

is the time at which we need to find the bike rider's distance

is the constant acceleration

is the bike rider's traveled distance

From (1) we can find :

   (3)

   (4)

   (5)

Now, we can substitute (5) in (2) and find the traveled distance :

(6)

(7)

Finally:

i don't know that i agree with that but what's the question ?

it is a negative acceleration