A 10 kg object is dropped from a height of 20 m. What is its speed just before i

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Question: A 10 kg object is dropped from a height of 20 m. What is its speed just before it hits the ground? (g = 10 m/s²) (2022)

Options:

Correct Answer: 20 m/s

Exam Year: 2022

Solution:

Using the formula v = √(2gh) = √(2 * 10 m/s² * 20 m) = √400 = 20 m/s.

A 10 kg object is dropped from a height of 20 m. What is its speed just before it hits the ground? (g = 10 m/s²) (2022)

A 10 kg object is dropped from a height of 20 m. What is its speed just before it hits the ground? (g = 10 m/s²) (2022)

Step 1: Identify the given values. The mass of the object is 10 kg, the height from which it is dropped is 20 m, and the acceleration due to gravity (g) is 10 m/s².
Step 2: Write down the formula to find the speed just before hitting the ground. The formula is v = √(2gh).
Step 3: Substitute the values into the formula. Replace g with 10 m/s² and h with 20 m: v = √(2 * 10 m/s² * 20 m).
Step 4: Calculate the value inside the square root. First, calculate 2 * 10 = 20, then multiply by 20 m: 20 * 20 = 400.
Step 5: Take the square root of 400. √400 = 20.
Step 6: State the final answer. The speed of the object just before it hits the ground is 20 m/s.

Kinematics – The question tests the understanding of the kinematic equations of motion, specifically the relationship between height, gravitational acceleration, and final velocity.
Energy Conservation – It also touches on the concept of energy conservation, where potential energy is converted to kinetic energy during free fall.