time period, frequency, graph of length l vs. T2 only; slope of the graph. Formula `T=2.pi.sqrt(l` [no derivation]. Only simple numerical problems.
The distance of a galaxy is 5·6 × 1025 m . Assuming the speed of light to be 3 × 108 `"ms"^-1`. Find the time taken by light to travel this distance .
[Hint : `"Time taken" = "Distance travelled"/"speed"`]
The time periods of two simple pendulums at a place are in the ratio 2:1. What will be the corresponding ratio of their lengths?
It takes 0.2 s for a pendulum bob to move from the mean position to one end. What is the time period of the pendulum?