27/03/2020 Forces and Moments(Senior Class Physics Study by Topics) 0Comments by Gate Academy Welcome to your Forces and Moments(Senior Class Physics Study by Topics) NAME EMAIL PHONE NUMBER 1. A body of mass 5kg initially at rest is acted upon by two mutually perpendicular forces 12N and 5N as shown in the figure. If the particle moves in the direction OA, calculate the magnitude of the acceleration. 0.40m/s²1.40m/s²3.40m/s²0.26m/s²2.60m/s²2. 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?250N235N205N165.3N3. In the diagram below, the resultant force along the x-axis is11.46N13.46N14.02N19.92N4. The figure below shows a block of wood resting on an inclined plane and at the point of sliding down the plane. Calculate the co-efficient of friction between the block and the plane.0.10.20.40.30.55. Which of the following bodies, each with centre of gravity G, lying on a horizontal table, is/are in unstable equilibrium?III & IV onlyI & IV onlyII onlyIII onlyII & III only6. A block of mass 50kg is given an initial speed of 5m/s on a rough horizontal floor. If it slides on the floor for 3m before it stops, calculate the coefficient of kinetic friction between the block and the floor. (g = 10m/s²)5/63/102/35/121/307. In the figure below, the three forces F_{1 , }F_{2} & F_{3} acting at O are in equilibrium. If the magnitude of F_{1} is 10.0N and the magnitude of F_{2} is 5.0N; find the magnitude of F_{3}15.0N10.0N13.2N26.4N8. 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 is4.0N0.4N64.0N6.4N9. The diagrams below show the positions of a cone. The position which can be described as neutral equilibrium is represented asY & Z onlyZ onlyX onlyY & X only10. Which of the following statements are correct about an object in equilibrium under parallel forces?I. the total clockwise moments of the forces about any point equals the total anticlockwise moments about the same point.II. the total forces in one direction equals the total forces in the opposite directionIII. the resolved components along the x-axis equals the resolved components along the y-axis.I & III onlyII & III onlyI, II & IIII & II only11. A man standing on a lift that is descending does not feel any weight becausethe lift is in vacuumthere is no gravitational pull on the man in the liftthere is no reaction from the floor of the liftthe inside of the lift is air tight12. What is the coefficient of static friction between a load of mass 0.75kg and a horizontal surface, if the limiting frictional force is 5N? (g = 10m/s²)0.153.750.0660.661.5013. The figure above shows a uniform circular object centre R and diameter PS. A circular section, centre Q and diameter PR is cut away from it. If PQRS is a straight line, where is the centre of gravity of the figure?a point between R & SRQa point between P & R14. When three coplanar non parallel forces are in equilibriumI. they can be represented in magnitude and direction by the three sides of a triangle triangle taken in orderII. their lines of action meet at a point III. the magnitude of any one force equals the magnitude of the resultant of the other twoIV. any one force is the equilibrant of the other two.Which of the statements above are correct?II & III onlyI & II onlyII, III & IV onlyI, III & IV onlyI, II, III & IV15. The limiting frictional force between two surfaces depends onI. the normal reaction between the surfacesII. the area of surfaces in contactIII. the relative velocity between the surfacesIV. the nature of the surfacesI & IV onlyIII onlyII onlyI onlyI & III only16. From the diagram shown below, if the forces are in equilibrium, what is the value of tension T?100.00N50.00N70.71N241.42N17. 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?9N18N20N200N18. A body of mass 2kg is placed on a rough inclined plane whose angle of inclination is 30º. Find the resultant force acting down the slope and the acceleration if a frictional force of 5N acts between the body and the inclined surface5N, 2.5m/s²10N, 2.5m/s²20N, 1.5m/s²15N, 0.5m/s²19. A boat is towed with a net force of 16000N acting at an angle of 60º to the water surface. If the boat moves with an acceleration of 20m/s², calculate its mass.400kg133.3kg692.8kg533.3kg20. 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 550g35g70g350g21. An 80mm column of a liquid is balanced by 120mm column of water in a Hare's apparatus. Calculate the density of the liquid (density of water = 1000kg/m³)66.7kg/m³1500kg/m³666.7kg/m³150kg/m³22. The figure below shows a see-saw which is exactly in balance. The weight of the people sitting on it are 50kg, Xkg and 15kg as shown. They sit at distance of 1.5m, 1.5m and 2m from the pivot respectively. The value of X is7030impossible to find26.53523. 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√3N4N2√3N8N2N24. Tireni stands on a spring scale placed in a lift. The lift descends at constant velocity. As a result, the scale reads a weightof zerothe same as the weight of Tirenigreater than the weight of Tireni by 1kggreater than the weight of Tireniless than the weight of Tireni25. Calculate the magnitude of the force required to just move a 20kg object along a horizontal surface if the co-efficient of friction is 0.20.4N40.0N4.0N400.0N26 out of 25Time is Up!