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| 1. | Two bodies P and Q of masses 10kg and 15kg respectively are connected by a light inextensible string.mass 15kg is at free fall pulling mass 10kg.P is placed on a tough surface of the coefficient of friction, 0.5. if the acceleration due to gravity is 10m/s², calculate the magnitude of the:(i) normal reaction on P(ii) frictional force between P and the surface(iii) tension in the string(iv) force which causes P and Q to accelerate(v)common acceleration of P and Q | 
| Answer» Explanation: HORIZONTAL force,F=600 N Mass of BODY A, m 1 =10 kg Mass of body B, m2=20 kg Total mass of the system, m=m1+m2=30 kg Using Newtons SECOND law of motion, the acceleration (a) produced in the system can be calculated as: F=ma a= m F = 30 600 =20m/s 2 
 When force F is applied on body A: The equation of motion can be written as: F−T=m 1 a T=F−(m 1 )a =600−10×20=400 N (i) When force F is applied on body B: The equation of motion can be written as: F−T=m 2 a T=F−(m 2 )a T=600−20×20=200 N (ii) which is DIFFERENT from value of T in case (i). Hence our answer depends on which mass end, the force is applied. | |