A tailor purchased a scissors fo length 25 cm through online shopping. He sent a feedback to the manfacturer saying 'I cannot cut the Jeans cloth even if I apply my maximum force 83.3 N on it, so please modify it, so please modify it without changing its length so that I can cut the Jeans cloth at least with my maximum effort'. If you are the manufacturer, how can you modify the scissors as per the feed-back given by the tailor? Initially fulcrum is exactly midway between two ends of the scissors and the minimum force required to cut the jeans cloth is 500 N. The position of the load should always be at 7.5 cm from the free end of load arm.

Answer

Fulcrum should be shifted to 2.5 cm towards old load position.

Explanation

(i) Before modification:

`MA=("Effort arm")/("Load arm")=(12.5)/(3)=2.5 cm`
Required `E=(L)/(MA)=(500)/(2.5)=200 N`
Required `E=(L)/(E)=(500)/(83.3)=6`
(ii) After modification

`MA=("Effort arm")/("Load arm")`
`6=(x)/(17.5-x)` `implies` New effort arm =15 cm
New load arm =17.5-15=2.5 cm
Fulcrum should be shifted to 2.5 cm towards old load position.