Explain the forces involved in a pendulum set up.

Just as the pendulum is released, the pendulum ball is at its maximum acceleration. The force due to gravity (weight) is acting vertically downwards, giving it a force component acting perpendicular to the string. This causes the acceleration. There is also tension in the string that opposes the component of the weight parallel to the string. In the stage of equilibrium, when the string is vertical, the forces of tension in the string and weight of the ball act in the same plane and cancel each other out. Hence there is no acceleration. There is no force component acting in the horizontal direction.At the second peak of the pendulum, the forces acting are the same as when the pendulum is first released, only acting in the opposite direction.

Related Physics A Level answers

All answers ▸

The Large Hadron Collider (LHC) of circumference 27km uses magnetic fields to accelerate a proton repeatedly in a circular path. Calculate the flux density of a uniform magnetic field required for the proton to travel at a tenth of the speed of light.


What is electromotive force (emf) and how can the emf of a battery be measured?


Topic - force as rate of change of momentum; (i) force on a wall due to water from a hose, (ii) force on a table as a rope is dropped onto it.


An object is let in free fall from a platform 20m high above Earth's surface. Describe the event in terms of energy and thus determine the speed of the object when it hits ground. Air resistance is negligible and gravitational acceleration is constant.