What is the time taken in one heart beat?

Write a note on heart beat.

A ball is thrown up with a speed of 9.8 ms^-1 What the time taken by the ball to reach the highest point.

Give the term for the period betwent he end of one heart beat to the end of next heart beat.

These questions consist of two statements each,printed as Assertion and Reason.While asnwering these questions you are required to choose any one of the following four responses. Assertion:Volume of blood ejected from the ventricles in one heart beat is called cardiac output. Reason:Cardiac output increases with the increase in body size of organism.

Note the relationship between the first two words and suggest a suitable word for the fourth place: Increase in heart beat : Sympathetic::Decrease in heart beat...... .

What is the time required for a first order reaction to be 99 % complete, compared to the time taken for the reaction to be 90 % complete ?