A boy weighing 40 kgf climbs up a stair of 30 steps each 20 cm high in 4 minutes and a girl weighing 30 kgf does the same in 3 minutes. Compare:
1) The work done by them.
2) The power developed by them.
A uniform half meter rule balances horizontally on a knife-edge at 29 cm mark when a weight of 20 gf is suspended from one end
1) Draw a diagram of the arrangement
2) What is the weight of the half meter rule?
The distance between two bodies is doubled. How is the magnitude of the gravitational force between them affected?