a pendulum is timed first for 20 swings and then for 50 swings . Time for 20nswings : 17.4 seconds .Time for 50 swings : 42.2 seconds . calculate the average time per swing in each case . the answers are slightly different. Suggest some possible experimental reasons for this​

The field between two charged parallel plates is kept constant. if the two plates are brought closer together, the potential difference between the two plates either a) decrease b) does not change c) increase?

Amagnetic field applies forces on: a)static chargesb)moving chargesc)water flow

Friction removes energy from objects in motion. which statement best describes how this works? a) friction transforms ke into thermal energy b) friction transfers thermal energy to ke c) friction transforms te into pe d) friction transforms pe into ke e) friction transfers ke into pe