11. The center of gravity of a semi-circle lies at a distance of __________ from its base measured along the vertical radius.
A. 3r/ 8
B. 4r/ 3π
12. The process of finding out the resultant force is called __________ of forces.
13. A weight of 1000 N can be lifted by an effort of 80 N. If the velocity ratio is 20, the machine is
14. In a framed structure, as shown in the below figure, the force in the member BC is
15. The potential energy of a vertically raised body is __________ the kinetic energy of a vertically falling body.
A. equal to
B. less than
C. greater than
16. If a number of forces acting at a point be represented in magnitude and direction by the three sides of a triangle, taken in order, then the forces are not in equilibrium.
17. The periodic time of a particle with simple harmonic motion is __________ proportional to the angular velocity.
18. The motion of a particle around a fixed axis is
D. translatory as well as rotary
19. A block of mass m1, placed on an inclined smooth plane is connected by a light string passing over a smooth pulley to mass m2, which moves vertically downwards as shown in the below figure. The tension in the string is
20. If a given force (or a given system of forces) acting on a body __________ the position of the body, but keeps it in equilibrium, then its effect is to produce internal stress in the body.
B. does not change