What is the Work Required to Raise a Chain to a Given Height?

[Sidthewall]

Homework Statement

A chain lyinh on the ground is 10 m long and its mass 80 kg. How much work is required to raise one end of the chain to a height of 6m.

Homework Equations

W = F x d
= mg x d
W = integral of mg dx from 1 to 6

The Attempt at a Solution

since mass is 80 kg and length is 10 m, linear density is 8kg/m

therefore m = 8 * change in distance
put it together

w = integrel of 8*change in x * 9.8 * dx from 0 to 6
= 78.4 * change in x * dx from 0 to 6
= 1411.2 Joules

AM i right?

p.s. sorry i am new at this i don't know how to get the actual functions for this

 

[ehild]

The result is correct. That "change of x" is the length of chain in air, and it is "x", the integration variable.

ehild