A 5 kg object is dropped from a height of 10 m. What is the total mechanical ene
Practice Questions
Q1
A 5 kg object is dropped from a height of 10 m. What is the total mechanical energy just before it hits the ground?
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Questions & Step-by-Step Solutions
A 5 kg object is dropped from a height of 10 m. What is the total mechanical energy just before it hits the ground?
Correct Answer: 490 J
Step 1: Identify the mass of the object. In this case, the mass (m) is 5 kg.
Step 2: Identify the height from which the object is dropped. The height (h) is 10 m.
Step 3: Use the formula for gravitational potential energy (PE), which is PE = mgh.
Step 4: Substitute the values into the formula: PE = 5 kg * 9.8 m/s² * 10 m.
Step 5: Calculate the potential energy: PE = 5 * 9.8 * 10 = 490 J.
Step 6: Understand that total mechanical energy is conserved, meaning it remains the same throughout the fall.
Step 7: Conclude that just before the object hits the ground, the total mechanical energy is still 490 J.
Potential Energy (PE) – The energy an object possesses due to its height above the ground, calculated using the formula PE = mgh.
Conservation of Mechanical Energy – The principle that the total mechanical energy (potential + kinetic) in a closed system remains constant if only conservative forces are acting.
