mtG Objective NCERT 92 on the 73 One end of a string of
Last updated: 6/8/2023
mtG Objective NCERT 92 on the 73 One end of a string of length I is connected to a 78 In the question number 77 the force acting e particle is particle of mass m and the other to a small peg on a smooth horizontal table If the particle moves in a circle with speed v the net force on the particle directed towards the centre is where T is the tension in the string a T Eng c T b T d 0 74 The mass of a bicycle rider along with the bicycle is 100 kg He wants to cross over a circular turn of radius 100 m with a speed of 10 m s If the coefficient of friction between the tyres and the road 80 A stone of mass 5 kg is tied to a string of lengs 10 m is whirled round in a horizontal circle What is the maximum speed with which the stone can be whirled around if the string can withstand maximum tension of 200 N a 10 ms c 20 m s mut is 0 6 the frictional force required by the rider to cross the turn is a 300 N c 1200 N my a mg T b mg T c mg f Feet 75 A stone of mass m tied to the end of a string revolves in a vertical circle of radius R The net forces at the lowest and highest points of the circle directed 81 A disc revolves with a speed 33 rev min and has vertically downwards are Lowest Point T d mg T a 1 cm c 4 cm mv R my mv R b 600 N d 150 N Highest Point mg T mg T mg T mg T T and v denote the tension and speed at the lowest point T and v denote corresponding values at the highest point b 2 cm d 8 cm R 76 A small object placed on a rotating horizontal turn table just slips when it is placed at a distance 4 cm from the axis of rotation If the angular velocity of the turn table is doubled the object slips when its distance from the axis of rotation is mv b 2 ms2 d 4 3 m s 77 A particle is moving on a circular path of 10 m radius At any instant of time its speed is 5 m st and the speed is increasing at a rate of 2 m s The magnitude of net acceleration at this instant is a 5 m s c 3 2 m s a m F c 2mma F 79 The coefficient of friction between the tyres and the road is 0 1 The maximum speed with which cyclist can take a circular turn of radius 3 m withou skidding is Take g 10 ms a 15 ms c 30 ms b mxo d 2mx 7 a A c Both A and B b 3 mst d 10 m st b 15 m s d 25 m s a radius of 15 cm Two coins A and B are placed a 4 cm and 14 cm away from the centre of the disc If the coefficient of friction between the coins and the disc is 0 15 which of the coins will revolve with the record c 10 ms 83 In the question b B d Neither A nor B 82 A circular racetrack of radius 300 m is banked at a angle of 15 The coefficient of friction between the wheels of a race car and the road is 0 2 The optimum speed of the race car to avoid wear and tear on its tyres is Take tan 15 0 27 g 10 ms2 a 10 3 ms b 9 10 ms d 2 10 ms number 82 the maximum permissible speed to avoid slipping is a 18 6 m s b 28 6 m sl d 48 6 ms c 38 6 m sl 84 An aircraft executes a horizontal loop at a speed of 720 km h with its wings banked at 15 What is the radius of the loop Take g 10 m s tan 15 0 27 a 14 8 km b 14 8 m c 29 6 km d 29 6 m 8