(a) The speed of a moving bus reduced from 45m/s to 5m/s with a uniform retardation of 10m/s\(^2\). Calculate the distance covered. (b) A bucket full of water with mass 16kg is pulled out of a well with a light inextensible rope. Find its acceleration when the tension in the rope is 240N. [Take g= 10m/s\(^2\)]
Explanation
(a) Using v\(^2\) =u\(^2\) + 2as (v=5m/s, u=45m/s) v\(^2\) = u\(^2\) -2as (For retardation) 5\(^2\)= 45\(^2\) -2(10)s 5\(^2\) - 45\(^2\) = 20s; 50(-40) = -20s -2000 = -20s; s=100m (b) Net force is T- W By Newton's second law: T-W=ma 240 - 26x10 = 16a 240 - 160 = 16a 80 16a a = 5m/s
