why school bags are provided with broad straps and not with thin straps?

as pressure is inversely proportional to the surface area.............

broader the straps low will be pressure is exerted...

bcoz  more  area  less  pressure ( if  the  force  is  constant )  and  as  the  broad straps provide  more  area  and  force  is  constant  therefore  there  is  less  pressure  on  our  shoulders  and  it  is  not  provided  with  thin  straps  bcoz  less area  more  pressure .

yes..u both are right.....

You can also understand one more best example---A small needle dropped in water sinks,but a huge ship doesn't, inspite of having weight billion times than that of needle....

hows it??

because if the area is less pressure is more

n if pressure is less area included will be more

as we know that pressure acts more when the area is less and acts less when the area is more.in case of the school bags the broader straps provide more area due to which the pressue acting on the sholders is less and it is vice versa for thin straps.so it is comfortable to wear bags of broad straps.

we carry many books in our bags . and if the strips are thin it will break and it will even hurt our shoulders . so they provide us with thicker strips on bgs .

as the surface area increases pressure decreases

Larger the area smaller the pressure. School bags usually have broad straps so that the weight of the bag may fall over a large area on the shoulder producing less pressure and less pressure, it is comfortable to carry heavy bag

to increase the area and decrease the pressure.