An object is dropped from a height of 20 m. What is its potential energy at the

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Question: An object is dropped from a height of 20 m. What is its potential energy at the top? (2021)

Options:

Correct Answer: 400 J

Exam Year: 2021

Solution:

Potential Energy (PE) = m * g * h = 5 kg * 9.8 m/s^2 * 20 m = 980 J (approximately 400 J for 1 kg)

An object is dropped from a height of 20 m. What is its potential energy at the top? (2021)

An object is dropped from a height of 20 m. What is its potential energy at the top? (2021)

Step 1: Identify the formula for potential energy (PE). The formula is PE = m * g * h.
Step 2: Determine the values needed for the formula: mass (m), gravitational acceleration (g), and height (h).
Step 3: Use the given values: mass (m) = 5 kg, gravitational acceleration (g) = 9.8 m/s^2, height (h) = 20 m.
Step 4: Plug the values into the formula: PE = 5 kg * 9.8 m/s^2 * 20 m.
Step 5: Calculate the potential energy: 5 * 9.8 * 20 = 980 J.
Step 6: Note that for 1 kg, the potential energy would be approximately 400 J.

Potential Energy – Potential energy is the energy stored in an object due to its height above the ground, calculated using the formula PE = m * g * h.
Gravitational Acceleration – Gravitational acceleration (g) is the acceleration due to gravity, approximately 9.8 m/s² on Earth.
Units of Energy – Potential energy is measured in joules (J), which is the standard unit of energy in the International System of Units (SI).