Question

Question about First Law of motion.
In tearing a paper towel or plastic bag from a roll, why is a sharp jerk more effective than a slow pull?

I cannot see why First law of motion is relevant to this physical phenomena.
Your help would be appreciated.

Maybe, because more force is added on a sharp, swift motion? an explanation would be great.

Answer 1

Ok I think I see why you don't see connection. The first law is: An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

Basically, this law is on inertia. From the equation F=ma, a quick, sharp jerk means a greater acceleration and a greater acceleration means a greater force. And it is force that tears the paper towel or plastic bag.

Answer 2

aha! Thank you; I did not think about the mathematical equation of force, F=ma.

Answer 3

You're welcome. Anything else? Are you new?

Answer 4

Very new. :/ I did not think about the acceleration part at all especially.

Answer 5

Ah I see. Google helps :) I meant, are you new to this site?

Answer 6

Ah yes, that too. I joined last October, but I am active here now with questions.. and studying ahead for school winter break.

Answer 7

during winter break, I mean. Thanks again. ^^

Answer 8

You're welcome. Welcome to OpenStudy. Do take time to read our CoC: http://openstudy.com/code-of-conduct and enjoy your stay. If you are satisfied with any question, please reward a medal to whoever you think deserves it and close the question. We also have a fan and testimony system. See you around :)

Answer 9

Ah, just read it. Thanks for good reminder for the site.

Answer 10

You're welcome :)