A 5 kg object is dropped from a height of 10 m. What is its speed just before it

A 5 kg object is dropped from a height of 10 m. What is its speed just before it hits the ground? (g = 9.8 m/s²)

A 5 kg object is dropped from a height of 10 m. What is its speed just before it hits the ground? (g = 9.8 m/s²)

Correct Answer: 14 m/s

Step 1: Identify the mass of the object, which is 5 kg.
Step 2: Identify the height from which the object is dropped, which is 10 m.
Step 3: Identify the acceleration due to gravity, which is 9.8 m/s².
Step 4: Use the formula for potential energy (PE) at the height: PE = mgh, where m is mass, g is gravity, and h is height.
Step 5: Calculate the potential energy: PE = 5 kg × 9.8 m/s² × 10 m.
Step 6: Calculate the potential energy: PE = 490 Joules.
Step 7: When the object falls, this potential energy converts to kinetic energy (KE) just before hitting the ground.
Step 8: Use the formula for kinetic energy: KE = 0.5mv².
Step 9: Set the potential energy equal to kinetic energy: 490 Joules = 0.5 × 5 kg × v².
Step 10: Solve for v²: 490 = 2.5v².
Step 11: Divide both sides by 2.5: v² = 490 / 2.5.
Step 12: Calculate v²: v² = 196.
Step 13: Take the square root of both sides to find v: v = √196.
Step 14: Calculate the final speed: v = 14 m/s.

Energy Conservation – The principle that the total energy in a closed system remains constant; in this case, potential energy is converted to kinetic energy.
Kinematics – The study of motion, particularly the relationship between displacement, velocity, acceleration, and time.