Worked Example: Finding Speed from Falling

Part of Gravitational Potential Energy · Section 9 of 16

Required PracticalUnit: EnergyGCSE

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)

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.

Practice questions for Gravitational Potential Energy

What is the value of gravitational field strength (g) on Earth?

A. 9.8 N/kg
B. 9.8 m/s
C. 10 kg/N
D. 6.7 N/kg

1 markfoundation

Explain how gravitational potential energy is related to an object's mass and height. Refer to the equation Ep = mgh in your answer.

3 marksstandard

Quick recall flashcards

GPE ∝ g

same object at same height on Moon has 1/6 the GPE as on Earth

GPE ∝ mass

double the mass, double the GPE (directly proportional)

How to Rearrange the GPE Equation

Key Definitions

15 questions on Gravitational Potential Energy: practise free

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