How this calculator works
A bob released from rest converts the gravitational energy associated with its vertical drop into kinetic energy at the bottom. The energy and speed calculation uses conservation of mechanical energy and does not require a small-angle approximation. The separate period and frequency outputs do assume small swings. Air drag, pivot losses and string mass are neglected.
Formula
E = m g h = m v_max²/2; v_max = sqrt(2gh); small-angle T = 2 pi sqrt(L/g).
Worked example
A 2 kg bob dropping 0.2 m with g = 10 m/s² gains 4 J and reaches 2 m/s. A 4 kg bob with 8 J available has the same 0.2 m drop and 2 m/s speed.
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Frequently asked questions
Is height the string length?
No. Height is the vertical difference between release and the lowest point; for release angle theta it is L(1 - cos theta).
Does mass affect maximum speed?
No, in this ideal model mass cancels from the speed equation. It still changes the kinetic energy.
Can a flexible string stay taut at any release angle?
No. Large release angles can require a rigid rod or another constraint. The geometric drop bound alone does not guarantee taut-string motion.