27/03/2020 Forces and Moments(Senior Class Physics Study by Topics) 27/03/2020 0Comments by Gate Academy Welcome to your Forces and Moments(Senior Class Physics Study by Topics) NAME EMAIL PHONE NUMBER 1. 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. 6.4Nm 3.2Nm 0.8Nm 1.6Nm 2. A 1000kg elevator is descending vertically with an acceleration of 1m/s². If the acceleration due to gravity is 10m/s², the tension in the suspending cable is 9000N 1.0N 11000N 10N 3. In the above diagram, the block just moves when the spring balance reads 15.0N. What is F? 10.0N 375.0N 15.0N 0.6N 40.0N 4. A cone in an unstable equilibrium has its potential energy decreased unchanged oscillating increased 5. 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 surfaces I & IV only I & III only I only II only III only 6. The diagrams below show the positions of a cone. The position which can be described as neutral equilibrium is represented as X only Y & Z only Z only Y & X only 7. A constant force of magnitude F, acts on an object of mass 0.4kg initially at rest at a point O. If the speed of the object when it has moved 50m from O is 500m/s, what is the value of F? 100N 0.04N 1000N 250N 8. The figure below shows four forces 3N, 10N, 3√3N and 6N acting on a particle P. The resultant of the four forces is 10√3N 10N 5√3N 5N 9. Which of the following statements is NOT correct?A moving vehicle comes to rest as a result of the frictional force between the brakes and the wheels the frictional force between the tyres and the surface on which the vehicle is moving the hot gases coming out of the exhaust pipe the resistance of a strong wind blowing against the vehicle the force applied in the opposite direction on the motion of the vehicle 10. 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? 4N 8N 2N 4√3N 2√3N 11. 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? 70cm 50cm 10cm 30cm 20cm 12. In the diagram below, the hanging mass M_{2} is adjusted until M_{1} is on the verge of sliding. The co-efficient of static friction between the mass M_{1} and the table is M2g / M1 M1g / M2 M2 / M1 M1 / M2 13. Tara pushes a 500kg box along a floor with a force of 2000N. If the velocity of the box is uniform, the coefficient of friction between the box and the floor is. (g = 10m/s²) 0.8 0.5 0.4 1.0 0.65 14. 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/3 4√3N/3 2√3N √3N 15. Consider the three forces acting at O and in equilibrium as shown above. Which of the following equations is/are correct?I. P_{1}Sinꝋ_{1} = P_{2}Sinꝋ_{2} II. P_{3} = P_{1}Cosꝋ_{1} + P_{2}Cosꝋ_{2}III. P_{1}Cosꝋ_{1} = P_{1}Cosꝋ_{2} III only I & III only II & III only II only I only 16. Two forces of magnitude 7N & 3N act at right angles to each other. The angle θ between resultant and the 7N force is given by sinθ = 3/7 cosθ = 3/7 cotθ = 3/7 tanθ = 3/7 17. The centre of gravity of a uniform triangular lamina is the point of intersection of all of the above the perpendicular bisectors of its sides the bisectors of its three sides the medians the altitudes 18. 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 4.9m/s² accelerate at 39.2m/s² accelerate at 9.8m/s² remain stationary 19. From the diagram shown below, if the forces are in equilibrium, what is the value of tension T? 241.42N 70.71N 100.00N 50.00N 20. 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} 10.0N 26.4N 13.2N 15.0N 21. 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) 5N 80N 8N 40N 22. 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) 1500kg/m³ 666.7kg/m³ 66.7kg/m³ 150kg/m³ 23. A force of 10N, drags a mass of 10kg on a horizontal table with an acceleration of 0.2m/s². If the acceleration due to gravity is 10m/s², the co-efficient of friction between the moving mass and the table is 0.02 0.08 0.20 0.80 24. 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 surface 15N, 0.5m/s² 10N, 2.5m/s² 20N, 1.5m/s² 5N, 2.5m/s² 25. 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 0.4N 40.0N 400.0N 4.0N 1 out of 25 Time is Up! Time's up