A man is running on the straightroad with the uniform velocity of 3m/s. Calculate acceleration produced by him.

acceleration =0 m/s^2

Explanation:

Acceleration is defined as the rate of change in velocity. If there’s no change in velocity, then the rate of change is zero, hence the acceleration is zero. The question says the man is running at a uniform velocity (i.e. he’s running at a steady speed in a fixed direction). This means his velocity is constant, or unchanging. Hence, his acceleration is zero.

Obviously everything I said in the above paragraph only concerns his horizontal velocity. To get even more specific, it only concerns the horizontal velocity of his centre of mass. Vertically, he is of course experiencing upward and downward downward acceleration due to how his feet push against the floor as he runs. And his limbs accelerate and decelerate as well, to allow him to run.

But looking at the man’s horizontal motion as a whole, and thinking of his motion as being entirely represented by his centre of mass, his acceleration is 0.

b. take periodic breaks and alternate between tasks.  

will increase work efficiency, and avoid health issues.