Question

How much work does it take to raise a `4 kg` weight `9 m`?

Answer 1

Work = force `*` distance

Explanation:

The force required to lift a 4 kg mass is it's weight, `F_g`, where

`F_g= m*g`, and `g` is the gravitational field strength, 9.8 N/kg

so

`W = F*d`
`W= m*g*d`
`W= 4kg*9.8N/(kg)*9m`

Note that some texts use 9.81 for `g`, and others suggest rounding up to 10 to simplify for purposes of focusing on conceptual principles, rather than calculation.