A man climbs a ladder carrying a concrete block of 5 kg. if the ladder makes an angle of 30 degree to the vertical and the ladder is 3 mtr long. How much work the man does on the block?

concrete block of 5 kg.
ladder makes an angle of 30 degree to the vertical
ladder is 3 mtr long.
how much work the man does on the block?


The y-component of the height is 3cos(30°) or 3sin(60°) as shown in the attachment. So the distance raised is 3cos(30°).

Work is force times distance

Force is mass times acceleration. In this case you're working against gravity.

And, as Unknown008 said, work is equal to potential energy which is given by mgh where g is the acceleration due to gravity (that's the acceleration you use in F=ma).