Frictional force measured using a spring balance (NCPQ)

A very simple demonstration of how to measure the frictional force on an object using a spring balance. When the object is pulled at constant speed the net force is zero so the applied force as shown by the reading on the scale is equal to the frictional force. This would only be true for a horizontal surface with the applied force applied horizontally. To calculate the coefficient of sliding friction, divide the frictional force by the weight of the object (the normal force as it is on a horizontal surface). Made by Dr Richard Walding, Moreton Bay College, Brisbane, Australia. Assisted by student Hannah. Textbook: New Century Physics for Queensland, 3rd ed, 2019. Oxford University press. Website: seniorphysics.com/ncpq