Question

A ball is thrown directly downward with an initial speed of 7.75 m/s from a height of 30.6 m. after what time interval does it strike the ground?

Answer 1

We can use the equation of motion:

$s = ut + 1/2$ ×  $a^{2}$

Since the acceleration and velocity are both downward, we will regard the downhill direction as positive.

$30=8t + 4.91t^{2}$

$4.91t^{2} + 8t - 30 = 0$

Solving the quadratic:

$t=1.79 s , t= - 3.42 s$

Negative time is not possible so the second value is discarded. Time taken $=1.79$ seconds

What is a time interval in physics?

A larger span of time can be broken up into several shorter, equal-length segments. These are referred to as time periods. Consider the scenario where you wished to gauge a car's speed over an hour-long trip. You could break up an hour into ten-minute segments. A time interval is the length of time between two specific points in time.

For example, "The time difference between 3:00 and 4:00 is 1 hour."

To learn more about time interval, visit:

brainly.com/question/6240163

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