A body of mass ' m ' is travelling with a velocity ' u '. When a constant retarding force ' F ' is applied, it comes to rest after travelling a distance ' s_1 '. If the initial velocity is ' 2u ', wi…

Question

A body of mass ' m ' is travelling with a velocity ' u '. When a constant retarding force ' F ' is applied, it comes to rest after travelling a distance ' s_1 '. If the initial velocity is ' 2u ', with the same force ' F, the distance travelled before it comes to rest is ' s_2.' Then

Accepted Answer

Correct answer: D. (d) : By applying constant retarding force F the body is brought to rest so v=0. Retardation, a=- Fm If s be distance travelled by the body before it comes to rest (called stopping distance). Using 3^ rd equation of motion v^2-u^2=2 as (0 )^2-u^2=2(- Fms) s= u^2m2F s ∝u^2 for the same of m ,F. ∴ s_1s_2= ( u2u )^2= 14 or s_2=4s_1

$A body of mass ' m' is travelling with a velocity ' u'. When a constant retarding force ' F' is applied, it comes to rest after travelling a distance ' s_{1}'. If the initial velocity is ' 2 u', with the same force ' F, the distance travelled before it comes to rest is ' s_{2} .' Then$

Solution

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