A simple pendulum of length 1 m has a bob of mass 100 g . At the lowest point in its path, the bob has a speed of 1.4 m/s . Determine the tension in the string at this instant.

Step-by-step solution

Given: Mass of the bob, m = 100 g = 0.1 kg Length of the pendulum, L = 1 m Speed at the lowest point, v = 1.4 m/s At the lowest point of the path, the net force acting towards the center of the circular path provides the necessary centripetal force. The forces acting on the bob are the tension T upwards and the weight mg downwards. T - mg = mv^2 L T = m (g + v^2 L ) Taking g = 9.8 m/s ^2 : T = 0.1 (9.8 + (1.4)^2 1 ) T = 0.1 (9.8 + 1.96) T = 0.1 11.76 = 1.176 N Rounding to one decimal place, we get T 1.2 N .