This required practical covers Worked Example: Finding Speed from Falling within Gravitational Potential Energy for GCSE Physics. Revise Gravitational Potential Energy in Energy for GCSE Physics with 15 exam-style questions and 6 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 9 of 16 in this topic. Revise both the method and the reason for each step, because practical questions often test understanding rather than pure recall.
🔬 Worked Example: Finding Speed from Falling
Question: A 2 kg ball is dropped from 5 m. Calculate its speed just before hitting the ground. (g = 10 N/kg, no air resistance)
Step 1: Calculate GPE at the top
GPE = mgh = 2 × 10 × 5 = 100 J
Step 2: Apply conservation of energy
At the bottom, all GPE has converted to KE (no air resistance)
So KE at bottom = 100 J
Step 3: Use KE equation to find speed
KE = ½mv² → 100 = ½ × 2 × v² → 100 = v²
v = √100 = 10 m/s
Quick Check: Calculate the GPE gained by a 5 kg object lifted 3 m. (g = 10 N/kg)
E_p = mgh = 5 × 10 × 3 = 150 J
Practice questions for Gravitational Potential Energy
What is the value of gravitational field strength (g) on Earth?
Explain how gravitational potential energy is related to an object's mass and height. Refer to the equation Ep = mgh in your answer.