Question

Maximum acceleration of the train in which a 50 kg box lying on its floor will remain stationary (Given: Co-efficient of static friction between the box and the train’s floor is 0.3 and g = 10 m s^-2 ) 

(1) 3.0 m s^-2 

(2) 15 m s^-2 

(3) 5.0 m s^-2 

(4) 1.5 m s^-2 

Answer 1

Correct option (1) 3.0 m s^-2

Explanation:

Friction accelerates the box.

F = ma

But F_max = μmg

So F_max = mamax

μmg = ma_max

a_max = μg = 0.3 × 10 = 3 m/s².