13.1b Ex4 MJ19 P42 Q1 Gravitational Torque | A2 G-fields | Cambridge A Level 9702 Physics

Example 4 - 9702/42/M/J/19: Two point masses are separated by a distance x in a vacuum. State an expression for the force F between the two masses M and m. State the name of any other symbol used. #9702s19p42 #A2gForceP4 #Lv3 (b) A small sphere S is attached to one end of a rod, as shown in Fig. 1.1. The rod hangs from a vertical thread and is horizontal. The distance from the centre of sphere S to the thread is 8.0 cm. A large sphere L is placed near to sphere S, as shown in Fig. 1.2. There is a force of attraction between spheres S and L, causing sphere S to move through a distance of 1.2 mm. The line joining the centres of S and L is normal to the rod. (i) Show that the angle θ through which the rod rotates is 1.5 × 10–2 rad. (ii) The rotation of the rod causes the thread to twist. The torque T (in N m) required to twist the thread through an angle β (in rad) is given by T = 9.3 × 10–10 × β.Calculate the torque in the thread when sphere L is positioned as shown in Fig. 1.2. (c) The distance between the centres of spheres S and L is 6.0 cm. The mass of sphere S is 7.5g and the mass of sphere L is 1.3 kg. (i) By equating the torque in (b)(ii) to the moment about the thread produced by gravitational attraction between the spheres, calculate a value for the gravitational constant. (ii) Suggest why the total force between the spheres may not be equal to the force calculated using Newton’s law of gravitation. #A2GravitationalFields Playlist:    • Ch13 Gravitational Fields | CAIE 9702 A2 P...   Instagram Pocket Guide (  / etphysics  ) More Resources (https://9702-physics.blogspot.com/) Support us! (  / etphysics  ) Tuition/Tutoring inquiries: Email: [email protected] Whatsapp: https://wa.me/60126679171 9702_w20_qp11 #CambridgeALevelPhysics