A Boy weighing 40 kg climbs up a stair of 30 steps each 20 cm high in 4 minutes and a girl weighing 30 kg does the same in 3 minutes. Compare:
The power developed by them.

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: (i)the work done by them.and (ii)the power developed by them .

A boy of mass 40 kg climbs up a flight of 30 steps each 20 cm high in 2 min and a girl of mass 30 kg does the same in 1.5 min. Compare : (i) the work done, and (ii) the power developed by them (g = 10 m s^(-2) )

A boy weighing 350 N climbs up 30 steps.each 20 cm high in 1 minute .Calculte: (i)The work done ,and (ii)the power spent.

A car of mass 1500 kg is lifted up a distance of 30 m by crane A in 0.5 minutes. The second crane B does the same jod in 1 minute . The ratio of their powers is

IT takes 20 s for a person A of mass 50 kg to climb up the stairs. While another person B of same mass does the same in 15 s compare (i) work done (ii) power developed by the person A and B.

A boy takes 3 minutes to lift a 20 litre water bucket from a 20 m deep well,while his father does it in 2 minutes ,(a)compare: (i)the work ,and (ii)power developed by them. (b)How much work rach deos?Take density of water = 10^(3) kg m^(-3) and g=9.8 N kg^(-1)

20 bags of cement, of 40 kg each, cost Rs 4400. Find the cost of 15 bags of cement weighing 30 kg each.

A boy mass 40 kg climbs up the stairs and reaches the roof at a height 8 m in 5 s. Calculate : (i)the force of gravity acting the boy . (ii) the work done by against the force of gravity . (iii)the power spent by the boy . (Take g=10 m S^(-2) )

A boy weighing 25 kgf climbs up from the first floor al a height of 3 m above the ground to the thind floor al a height of 9 m above the ground. What will be the increase in his gravitational potential energy? (Take g = 10 N kg^(-1) )