Video narration
Cycle tez kaise hoti hai, chalti kyon rahti hai, aur zameen ko peeche dhakelkar aage kaise badhti hai? Speed batati hai ki cycle kitni tez hai; velocity mein disha bhi shamil hai. Tez hona acceleration hai; dheema hona ya mudna bhi, kyonki velocity badalti hai. Momentum ka sutra p = mv hai - mass aur velocity ka gunanphal. Bhaari ya tez cycle rokna kathin hota hai. Inertia koi force nahin; motion badalne ka virodh karne ki pravritti hai. Tyre zameen ko peeche dhakelta hai, zameen tyre ko barabar bal se aage dhakelti hai. Yahi Newton's third law hai: bal barabar aur vipreet hote hain, lekin alag vastuon par lagte hain. Yaani velocity motion batati hai, acceleration use badalti hai, momentum gati ka maap hai, aur inertia badlav ka virodh karti hai. To cycle acceleration se tez hoti hai, momentum ke saath chalti rahti hai, inertia badlav ka virodh karti hai; aur zameen, tyre ke peeche dhakke ke jawab mein, barabar bal se aage dhakelti hai.