JC · A-Level H2 Physics
Spring Launcher
Round 1/6Score: 0
Launch lab
Mass
Spring stiffness
Target
Model
0.050 m
100 W
50%
Solve the launch challenge.
Force and motion
ForceStored-energy area
Area means work
The area under an F–x graph is work in joules, even when the spring is not Hookean.
The physics
Hookean spring: F = kx; Eₑ = ½kx².
General spring: Eₑ = ∫F(x) dx, the area under its force–displacement graph.
Work–energy theorem: net work = change in kinetic energy.
Ideal launch: Eₑ = ½mv², or Eₑ = mgh on a smooth incline.
Power P = work ÷ time = Fv at constant speed. Efficiency η = useful output power ÷ input power × 100%.
g = 10 N/kg. Models ignore friction, spring mass and drag. The launch graph is numerically simulated for a spring starting from rest.