If your bike wheel of radius 40 cm takes 10s for one complete rotation, what is your bike speed?

8π.

Explanation:

The wheel's radius is 40 cm, so the perimeter of the wheel is 80π cm. ( because perimeter equals 2 * radius * π )

According to the formula :

distance = speed * time

We can know that the distance is perimeter of the wheel ( because when the wheel completes a rotation, it also goes forward a distance of the perimeter ) , now we got : 80π = speed * 10,

so the answer is 8π.

c. convergent boundary.

explanation:

the independent variable, the one that is intentionally manipulated, is whether or not the car hits the barrier.

the dependent variable, the one that you measure the response in, is the distance that the washers travel.