A ball is thrown horizontally from a height of 45 m. How long does it take to hi

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Question: A ball is thrown horizontally from a height of 45 m. How long does it take to hit the ground? (Assume g = 9.8 m/s²)

Options:

Correct Answer: 4 s

Solution:

Using the formula t = √(2h/g), where h = 45 m and g = 9.8 m/s², we get t = √(2 * 45 / 9.8) ≈ 3.03 s.

A ball is thrown horizontally from a height of 45 m. How long does it take to hit the ground? (Assume g = 9.8 m/s²)

A ball is thrown horizontally from a height of 45 m. How long does it take to hit the ground? (Assume g = 9.8 m/s²)

Step 1: Identify the height from which the ball is thrown. In this case, the height (h) is 45 meters.
Step 2: Identify the acceleration due to gravity (g). Here, g is given as 9.8 m/s².
Step 3: Use the formula to calculate the time (t) it takes for the ball to hit the ground. The formula is t = √(2h/g).
Step 4: Substitute the values into the formula: t = √(2 * 45 / 9.8).
Step 5: Calculate the value inside the square root: 2 * 45 = 90, then divide by 9.8, which gives approximately 9.18.
Step 6: Take the square root of 9.18 to find t. The square root of 9.18 is approximately 3.03 seconds.
Step 7: Conclude that it takes about 3.03 seconds for the ball to hit the ground.

Projectile Motion – The question tests understanding of the time of flight for an object in free fall, independent of horizontal motion.
Kinematic Equations – Application of the kinematic equation for vertical motion to determine the time taken to fall a certain height.