Work Power Energy Question 3
Question 3 - 2024 (29 Jan Shift 1)
A block of mass $100 kg$ slides over a distance of $10 m$ on a horizontal surface. If the co-efficient of friction between the surfaces is 0.4 , then the work done against friction (in $J$ ) is :
(1) 4200
(2) 3900
(3) 4000
(4) 4500
Show Answer
Answer: (3)
Solution:
Given $m=100 kg$
$s=10 m$
$\mu=0.4$
As $f=\mu mg=0.4 \times 100 \times 10=400 N$
Now $W=f . s=400 \times 10=4000 J$
