Identify whether the following statements describe a change in acceleration. explain your response.

a. A car stopped at a stop sign.  

d. A person running at 5 meters/second along a curving path

Explanation:

There is acceleration in all cases velocity changes. In options b and c the speed is constant, then there is no acceleration. In option a, the car was moving and then stop, therefore, its speed decrease to zero, and that represent an acceleration. In option d, the magnitude of the velocity doesn't change, nevertheless its direction changes along the curving path (remember that velocity is a vector quantity), therefore, the person receive centripetal acceleration .

c. rb

explanation:

the atomic radius of a chemical element is a measure of the size of its atoms, usually the mean or typical distance from the center of the nucleus to the boundary of the surrounding shells of electrons.

here we know that ball will drop down by total distance 3.2 m

so here we know that

now using kinematics

now in the same time it will cover horizontal distance of 0.75 m

so speed of the ball will be