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! ✓
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.
Practice questions for Kinetic Energy
Which of the following objects has kinetic energy stored in its kinetic energy store?
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.