Final answer:
To find the time interval it takes for the ball to strike the ground after being thrown downward, you can use the formula for the final position of an object in free fall. Solve the equation involving the initial height, initial velocity, acceleration due to gravity, and time to find the time interval it takes for the ball to strike the ground.
Step-by-step explanation:
In this problem, you need to determine the time interval it takes for a ball to strike the ground after being thrown downward.
Given:
- Initial speed (v0) = -7.45 m/s (downward)
- Initial height (y0) = 30.7 m
- Acceleration due to gravity (g) = -9.8 m/s2
To find the time interval, you can use the formula for the final position of an object in free fall:
y = y0 + v0t + 0.5gt2
Since the ball is thrown downward, the initial velocity is negative. Plug in the given values and solve for t:
0 = 30.7 - 7.45t + 0.5(-9.8)t2
This is a quadratic equation, which can be solved using the quadratic formula or factoring. Once you solve for t, you will have the time interval it takes for the ball to strike the ground.