How to use the pendulum bob speed and tension calculator
Find the speed and string tension of a pendulum bob at its lowest point when released from an angle. Enter string length, release angle from vertical, bob mass in the fields above; the speed at lowest point, tension at lowest point are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “pendulum speed at bottom”, “pendulum tension”, “swinging bob”, “calculate pendulum bob speed and tension”, “find speed at lowest point”.
Formula
Variables
- L — String length (m)
- th — Release angle from vertical (°)
- m — Bob mass (kg)
Worked example
With string length = 2 m, release angle from vertical = 30 °, bob mass = 1 kg, the calculator gives speed at lowest point ≈ 2.292459 m/s; tension at lowest point ≈ 12.43433 N.
Frequently asked questions
What is the pendulum bob speed and tension calculator used for?
Find the speed and string tension of a pendulum bob at its lowest point when released from an angle. It helps with questions such as “pendulum speed at bottom”, “pendulum tension”, “swinging bob”.
What is the formula for the pendulum bob speed and tension calculation?
Speed at lowest point (m/s) = √(2 × GRAV × L × (1-cos(th))). Tension at lowest point (N) = m × GRAV × (3-2 × cos(th)). Here L is string length (m), th is release angle from vertical (°), m is bob mass (kg).
What inputs do I need for the pendulum bob speed and tension calculator?
You need string length in m, release angle from vertical in °, bob mass in kg. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the pendulum bob speed and tension calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the pendulum bob speed and tension result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.