Abucket of water of mass 10 kg is pulled at constant velocity up to a platform 30 meters above the ground. this takes 10 minutes, during which time 4 kg of water drips out at a steady rate through a hole in the bottom. find the work needed to raise the bucket to the platform. (use =9.8m/s2.)

W = 2352 J

Explanation:

Given that:

Here, according to the given situation the bucket moves at the rate,

The mass varies with the time as,

Consider the time interval between t and t + ∆t. During this time the bucket moves a distance

∆x =  3∆t meters

So, during this interval change in work done,

∆W = m.g∆x

For work calculation:

compass can be used day and night, cloudy or sunny

b. a lightning bug, plug of grass, and a worm