is it possible to open a pen cap with one finger?
Kindly refer the following link to get your answer :-
https://www.meritnation.com/ask-answer/question/is-it-posible-to-open-a-pen-cap-with-just-one-finger-why/system-of-particles-and-rotational-motion/6761521
https://www.meritnation.com/ask-answer/question/is-it-posible-to-open-a-pen-cap-with-just-one-finger-why/system-of-particles-and-rotational-motion/6761521