Worked Example: Finding Speed from KE

Part of Kinetic Energy · Section 7 of 15

Required PracticalUnit: EnergyGCSE

This required practical covers Worked Example: Finding Speed from KE within Kinetic Energy for GCSE Physics. Revise Kinetic Energy in Energy for GCSE Physics with 15 exam-style questions and 30 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 7 of 15 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 KE

Question: A 1500 kg car has kinetic energy of 675,000 J. Calculate its speed.

Step 1: Write the equation

Ek = ½mv²

Step 2: Substitute known values

675,000 = ½ × 1500 × v²

Step 3: Simplify

675,000 = 750 × v²

Step 4: Rearrange for v²

v² = 675,000 ÷ 750 = 900

Step 5: Square root to find v

v = √900 = 30 m/s

💡 Check: Does ½ × 1500 × 30² = 675,000? Yes! ✓

Practice questions for Kinetic Energy

Which of the following objects has kinetic energy stored in its kinetic energy store?

  • A. A book sitting on a shelf
  • B. A stretched elastic band
  • C. A car moving along a road
  • D. A battery connected to nothing
1 markfoundation

A car travels at 20 m/s. The driver then doubles their speed to 40 m/s. Explain what happens to the kinetic energy of the car and by what factor it changes.

2 marksstandard

Quick recall flashcards

What is kinetic energy?
The energy stored in any object due to its motion. If it's moving, it has kinetic energy.
Kinetic energy equation?
Ek = ½mv² where m = mass (kg), v = velocity (m/s), Ek = kinetic energy (J)

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