A crane 'A' lifts a heavy load in 5 seconds, whereas another crane 'B' does the same work in 2 seconds. Compare the power of crane 'A' to that of crane 'B'.

A man does a given amount of work in 10 sec. Another man does the same amount of work in 20 sec. The ratio of the output power of first man to the second man 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 man raises a box of mass 50 kg to a height of 2 m 10 s,while another man raises the same box to the same height in 50 s. (a)Compare :(i)the work done ,and (ii)the power developed by them . Take g=10 N kg^(-1)

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

A coolie 1.5 m tall raises a load of 80 kg in 2 sec from the ground to his head and then walks a distance of 40 m in another 2 second. The power developed by the coolie is : (g = 10 m//s^(2))

One coolie takes 1min to raise a box through a height of 2m . Another one takes 30s for the same job and does the same amount of work. Which one of the two has greater power and which one uses greater enegy?

A crane lifts a mass of 100 kg to a height of 10 m in 20 s. The power of the crane is (Take g = 10 m s^(-2) )

Discuss whether any work is being done by each of the following agents and, if so, whether the work is positive or negative: (a) a chicken scratching the ground, (b) a person studying, (c) a crane lifting a bucket of concrete, (d) the gravitational force on the bucket in part (c), and (e) the leg muscles of a person in the act of sitting down.

A tuning fork 'A' produces 6 beats per second with another fork 'B'. On loading 'B' with a little wax, it produces 5 beats per second with 'A'. If the frequency of 'A'is 256 Hz find the frequency of 'B?.

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) )