Static friction force between 10kg and 40kg block,
Fs=µsR=0.6×mg =0.6×10×9.8=58.8N Here, we see that the applied force (F=100N) is greater than friction force, hence 10kg block will start motion due to application of 100N force. Due to motion, kinetic friction force fk=µkR=0.4mg =0.4×10×9.8=39.2N 40kg body experiences a force of fk=39.2N ∴ Acceleration of 40kg slab a=