The **value **of t at a height of 11 feet is **0.36 sec** when the ball is going **upwards **and** 1.39 seconds** when the ball is coming **downwards**.

<h3>What is a quadratic equation?</h3>

A **quadratic **equation is an equation whose **leading **coefficient is of second **degree **also the **equation **has only one unknown while it has 3 unknown numbers.

It is written in the form of** ax²+bx+c.**

Given that the **height **of the ball at **time **t is given by the function,

where t is in **seconds **and h is in feet.

Now, the **height **of the ball is given to be 11 feet, therefore, **substituting **the value of h in the **function **as 11,

Now, solving the given **quadratic equation,** we will get,

Hence, the **value **of t at a height of 11 feet is **0.36 sec** when the ball is going **upwards **and** 1.39 seconds** when the ball is coming **downwards**.

Learn more about **Quadratic Equations:**

brainly.com/question/2263981

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