Q. 35 A block weighing 200 N is in contact with a level plane whose coefficients of static and kinetic friction are 0.4 and 0.2, respectively. The block is acted upon by a horizontal force (in newton) P= 10t, where t denotes the time in seconds. The velocity (in m/s) of the block attained after 10 seconds is Q. 36 A slider crank mechanism has slider mass of 10 kg, stroke of 0.2 m and rotates with a uniform angular velocity of 10 rad/s. The primary inertia forces of the slider are partially balanced by a revolving mass of 6 kg at the crank, placed at a distance equal to crank radius. Neglect the mass of connecting rod and crank. When the crank angle (with respect to slider axis) is 30, the unbalanced force (in newton) normal to the slider axis is Q. 38 A rigid uniform rod AB of length L and mass m is hinged at C such that AC L/3, CB= 2L/3. Ends A and B are supported by springs of spring constant k. The natural frequency of the system is given by 332 k A w L/32L/3 (A) k 2m 2k (C) k ww B datas.com (D) 5k m Q. 39 A hydrodynamic journal bearing is subject to 2000 N load at a rotational speed of 2000 rpm. Both bearing bore diameter and length are 40 mm. If radial clearance is 20 m and bearing is lubricated with an oil having viscosity 0.03 Pa.s, the Sommerfeld number of the bearing is Q. 40 A 200 mm long, stress free rod at room temperature is held between two immovable rigid walls. The temperature of the rod is uniformly raised by 250C . If the Young's modulus and coefficient of thermal expansion are 200 GPa and 1 x 10-5/C, respectively, the magnitude of the longitudinal stress (in MPs) developed in the rod is