Welcome to your Forces and Moments(Senior Class Physics Study by Topics) NAME EMAIL PHONE NUMBER 1. A body of mass 4kg is on the point of slipping down a plane which is inclined at 30° to the horizontal. What force, parallel to the plane, will just move it up the plane? (g = 10m/s²) 8N 80N 5N 40N2. A mass of 2kg on a surface (μ = 1/2) is connected to a second mass of 4kg over a frictionless pulley as shown in the diagram. If the acceleration due to gravity is 9.8m/s², then the masses will accelerate at 19.6m/s² accelerate at 9.8m/s² accelerate at 39.2m/s² remain stationary accelerate at 4.9m/s²3. In the figure below, the three forces F1 , F2 & F3 acting at O are in equilibrium. If the magnitude of F1 is 10.0N and the magnitude of F2 is 5.0N; find the magnitude of F3 26.4N 10.0N 13.2N 15.0N4. The co-efficient of static friction between a 40kg crate and a concrete surface is 0.25. Find the magnitude of the minimum force needed to keep the crate stationary on the concrete base inclined at 45° to the horizontal (g = 10m/s²) 400N 283N 300N 212N5. Which of the following bodies, each with centre of gravity G, lying on a horizontal table, is/are in unstable equilibrium? I & IV only II & III only III only II only III & IV only6. Calculate the magnitude of the force required to just move a 20kg object along a horizontal surface if the co-efficient of friction is 0.2 4.0N 0.4N 40.0N 400.0N7. A force of 20N, applied parallel to the surface of a horizontal table is just sufficient to make a block of mass 4kg move on the table. What is the coefficient of friction between the surfaces of the block and the table? (g = 10m/s²) 8.0 2.0 5.0 0.5 0.28. In the diagram below, MN is perpendicular ON and MP. What is the difference between the moment about N of the force 20N, applied along MP and its moment about O? 8Nm 2Nm 0Nm 4Nm 6Nm9. A uniform meter rule QR is balanced on a knife edge which is 55cm from R. When a mass of 10g is hung at P as shown below, the mass of the meter rule is 550g 70g 350g 35g10. Two forces each of 4N act on opposite sides of a rectangular plane as shown in the diagram below. Calculate the magnitude of the couple acting on the plane. 1.6Nm 3.2Nm 6.4Nm 0.8Nm11. A wooden block of weight 16N is placed on a rough surface. If the co-efficient of friction between both surfaces is 0.25, the least horizontal force required to move the block is 0.4N 4.0N 64.0N 6.4N12. The value of T in the figure below is 20N 11.8N 10N 40N13. A boy pulls a nail from the wall with a string tied to the nail. The string is inclined at an angle of 60° to the wall. If the tension in the string is 4N, what is the effective force used in pulling the nail? 4√3N 4N 2√3N 2N 8N14. The term torque means... two equal and opposite forces whose lines of action do not coincide the equilibrant of two concurrent forces two coplanar forces at right angles to each other the moment of a couple about an axis the resultant of several forces acting on a body in equilibrium15. A body of weight W rests on a smooth plane inclined at an angle of θ° to the horizontal. What is the resolved part of the weight in Newtons along the plane? Wtanθ Wsecθ Wcosθ Wsinθ16. An object of mass 80kg is pulled on a horizontal rough ground by a force of 500N. Find the coefficient of static friction. (g = 10m/s²) 1.00 0.625 0.80 0.4017. In the above diagram, the block just moves when the spring balance reads 15.0N. What is F? 15.0N 0.6N 40.0N 375.0N 10.0N18. A small trolley is set in motion on a horizontal surface by a force of 250N applied by means of a rope inclined at an angle of 20° to the horizontal. What horizontal force may be used instead? 250N 165.3N 205N 235N19. In the diagram below, the hanging mass M2 is adjusted until M1 is on the verge of sliding. The co-efficient of static friction between the mass M1 and the table is M1g / M2 M2 / M1 M1 / M2 M2g / M120. A block of mass 50kg slides down a plane inclined at an angle of 30° to the horizontal. If the co-efficient of friction is 0.4, calculate the frictional force between the two surfaces. (g = 10m/s²) 200.00N 62.50N 173.21N 100.00N21. A weight of 1000g hangs from a lever 20cm to the right of the fulcrum. At the left is a 500g weight 20cm from the fulcrum. If a 200g weight is Ycm away from the fulcrum, what is the value of Y that will make the lever balance? 30cm 10cm 20cm 70cm 50cm22. Which of the following types of motion is produced by a couple? rotational random oscillatory translational23. A body was slightly displaced from its equilibrium position. Which one of the following is a condition for its stable equilibrium an increase in the potential energy of the body an increase in the kinetic energy of the body an increase in the weight of the body a decrease in the potential energy of the body24. In the diagram below, a lever of length 200m is used to lift a load of mass 180kg. The pivot at P is 20m from the load. What minimum force, F, must be applied at the end of the lever? 18N 20N 9N 200N25. Two horizontal forces, 10N and 8N and another force, F inclined at 30° to the vertical acting as shown in the diagram below, keep the body P in equilibrium. The weight of the body is 2√3N 4√3N/3 √3N 2√3N/326 out of 25Time is Up!