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Miracle Learning Centre Science Tuition Question on Turning Effects of Force. (O Level Science Tuition/IP Science Tuition/Secondary Science Tuition)

1. Fig (a) and Fig (b) show cranes carrying similar loads but with different orientations of the arm.

a) Which of the above figures allow a greater load to be carried without the crane tilting to the right? Explain your answer. _________________________________________________________ _________________________________________________________ b) The load has a weight of 800 N. The load needs to be turned upright by applying the force F with the load turning about point A as shown in Fig (c). You can assume that the centre of mass is located at the centre of the load.

(i) Calculate the mass of the load. (ii) Calculate the minimum force F needed to just turn the load about point A.

(a) The diagram shows a mass moving at a steady speed of 0.1 m s-1 when the applied force F is 12 N. (i) Draw in the other horizontal force which is acting on the mass and indicate its line of action and magnitude. (ii) Calculate the work done in moving the mass 1.5 m along the surface. (b) Force F is now increased to 18 N and acts for 0.2 s. Assuming that all other forces remain constant, calculate (i) the acceleration produced, (ii) the highest speed reached. Miracle Learning Centre Answer to Science Tuition Question on Turning Effects of Force. (O Level Science Tuition/IP Science Tuition/Secondary Science Tuition) 1. a) Fig (b) as the perpendicular distance of the load to the pivot is smaller than in Fig (a). b) (i) Mass = 80 kg (ii) Anticlockwise moments = Clockwise moments F x 0.6 = 800 x 0.5 F = 667 N

(aii) Work done = F x s = 12 x 1.5 = 18 J (bi) Resultant force = 18-12 = 6 N A = Resultant/mass = 6/3 = 2m/s2 © Highest speed = u + at [1]= 0.1 + 2x 0.2 = 0.5 m/s Learn from our Science Tuition Questions and Answers. Miracle Learning Centre Call 6463 8756 or sms 8128 8342/9839 9908. (Specialist in Science and Maths) for Primary, Secondary and JC levels. Miracle Learning Centre specialises in Science tuition, Maths tuition, Chemistry tuition and Physics tuition classes.