Sri Lankan A-Level · Free Worksheet
Work, Power and Energy
Work done by a constant force and the conservation of energy — mechanics practice for Combined Mathematics, Sri Lankan G.C.E. Advanced Level.
What's inside
- A short recap of the method before the questions start
- Practice questions ordered from easiest to hardest
- Space to show full working, plus an answer key
Preview
Sample questions
Question 1
A constant force of 25 N acts on an object, moving it 12 m in the direction of the force. Calculate the work done.
Show worked solution
Work done = force × distance = 25 × 12 = 300 J.
Question 2
A 2 kg object falls freely from rest through a height of 5 m. Using energy conservation (g = 10 m s⁻²), find its speed just before it lands.
Show worked solution
Loss in gravitational PE converts entirely to KE: mgh = ½mv². So v² = 2gh = 2 × 10 × 5 = 100, giving v = 10 m/s.
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