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. In the figure, MN is a light uniform meter rule pivoted at O, the 80cm mark. A load of 3.0kg is suspended on the rule at L, the 10cm mark. If the rule is kept in equilibrium by a string RP, fixed at P and attached to the rule at R, the 20cm mark, then the tension T in the string is.....30N70N35N60N34N2. A body rolls down a slope from a height of 100m. Its velocity at the foot of the slope is 20m/s. What percentage of its initial potential energy is converted into kinetic energy?20%35%40%15%3. A box of mass 40kg is being dragged along the floor by a rope inclined at 60° to the horizontal. The frictional force between the box and the floor is 100N and the tension on the rope is 300N. How much work is done in dragging the box through a distance of 4m?400J680J100J200J4. Find the resultant5N, N 65° W17N, S 61.9° E3N, N 75.2° E15N, S 43.4° W5. 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√3N2N4N2√3N8N6. Calculate the apparent weight loss of a man weighing 70kg in an elevator moving downwards with an acceleration of 1.5m/s². (g = 10m/s²)686N581N105N595N7. 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.0.20.10.40.50.38. A block of mass 2kg resting on a smooth horizontal plane is acted upon simultaneously by two forces, 10N due North and 10N due East. The magnitude of the acceleration produced by the forces on the block is7.07m/s²14.10m/s²20.00m/s²10.00m/s²0.10m/s²9. 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)212N300N283N400N10. 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)0.800.6251.000.4011. Which of the following is in a neutral equilibrium?the beam of a balance in usea cone resting on its slant edgea heavy based table lampa heavy weight suspended on a string12. Tireni stands on a spring scale placed in a lift. The lift descends at constant velocity. As a result, the scale reads a weightof zerogreater than the weight of Tireni by 1kgless than the weight of Tirenithe same as the weight of Tirenigreater than the weight of Tireni13. 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?WtanθWcosθWsinθWsecθ14. A block of mass M is held in equilibrium against a vertical wall by a horizontal force. If the co-efficient of friction between the block and the wall is μ, the minimum value of the horizontal force ismg/μ(1 - μ)mg(1 + μ)mgμmg15. 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 is6.4N0.4N64.0N4.0N16. Which of the following statements is NOT correct?A moving vehicle comes to rest as a result ofthe resistance of a strong wind blowing against the vehiclethe force applied in the opposite direction on the motion of the vehiclethe hot gases coming out of the exhaust pipethe frictional force between the tyres and the surface on which the vehicle is movingthe frictional force between the brakes and the wheels17. The figure below shows a block of wood of weight W just on the point of sliding down on a rough plane inclined at an angle θ to the horizontal . What is the co-efficient of friction between the block and the plane?WcosθtanθWsinθWtanθcosθ18. The figure above shows two connected bodies of masses M_{1} and M_{2} in equilibrium under gravity. The tension in the upper string isM2gM1g(M1 + M2)g(M1 - M2)g19. 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 isM2g / M1M1 / M2M2 / M1M1g / M220. 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?RQa point between P & Ra point between R & S21. 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)62.50N200.00N100.00N173.21N22. Two forces 3N and 4N act on a body in directions due north and due east respectively. Calculate their equilibrant.5N, 53° west of south7N, 37° west of north5N, 37° north of east5N, 53° east of north7N, 37° south of west23. Two masses 40g and 60g respectively, are attached firmly to the ends of a light meter rule. The centre of gravity of the system is60cm from the heavier mass40cm from the heavier mass40cm from the lighter massindeterminate because the meter rule is lightat the mid point of the meter rule24. 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 4√3N/32√3N2√3N/3√3N25. Which of the following bodies, each with centre of gravity G, lying on a horizontal table, is/are in unstable equilibrium?III onlyII onlyIII & IV onlyI & IV onlyII & III only26 out of 25Time is Up! Time's up