**Answer:**

**Part(a): The average acceleration is **** during the first 6s.**

**Part(b): The average acceleration from 6s to 8s is zero.**

**Explanation:**

**Part(a):**

The **average acceleration** is defined as the rate at which velocity is changing with respect to time. So if '', '' and '' represents the initial velocity, final velocity, and average acceleration of a particle, then mathematically

where '' is the time taken by the particle to achieve the velocity '' starting from initial velocity ''

Given in the problem, .

So the average acceleration() during the first 6 s will be

**Part(b):**

During the time between 6 s to 8 s, as mentioned in the problem, the sprinter maintains the constant velocity. So the average acceleration during this time interval will be **zero.**

D =vt

so

1485m = (330m/s) t

1485/330 = 4.5s

4.5 s is the amount of time! Hope this helped.

**Answer:**

Y will experience the most acceleration

**Explanation:**

Because using F=ma, you can rearrange the formula to show that acceleration equals force over mass. You then do the calculations for each of the objects, and y will be your answer.

**Answer:**

water

**Explanation:**

coz out of the choices water is the only one that is not an element.

water formula is H2O

You will need too know the mass and velocity