Question

What is the amount of work done by a boy when 1) he holds a bundle of books of mass 2 kg for 5 min ? 2) he lifts up the same bundle of books through I m to keep it on his study table

Answer 1

$\huge\color{red}\boxed{Answer}$

case 1

no work has been done

case 2

given

mass = 2kg

s = 1m

$\la</strong><strong>r</strong><strong>g</strong><strong>e</strong><strong>\co</strong><strong>l</strong><strong>o</strong><strong>r</strong><strong>{</strong><strong>brown</strong><strong>}</strong><strong>\</strong><strong>b</strong><strong>o</strong><strong>x</strong><strong>e</strong><strong>d</strong><strong>{</strong><strong>W</strong><strong>=</strong><strong>Fs</strong><strong>}$

To find force

$\large\color{green}\boxed{F=ma}$

F= 2(10)

F = 20 m/s²

by putting value

W = 20 x 1

w = 20j

$\</strong><strong>h</strong><strong>u</strong><strong>g</strong><strong>e</strong><strong>\</strong><strong>u</strong><strong>n</strong><strong>d</strong><strong>e</strong><strong>r</strong><strong>l</strong><strong>i</strong><strong>n</strong><strong>e</strong><strong>\color{</strong><strong>indigo</strong><strong>}{</strong><strong>expal</strong><strong>nation</strong><strong>}$

• in 1st case no dispalcement happen so no work done coz W = 20 x 0 = 0

• in case 2 we have to find force first

• as we are lifting the book to hight we are doing work anginst gravity

• so we take acceletion as 10m/s²

• now put value is formula and get answers as 20jouls

hope it helps you

be brainly