Tiêu đề 04. MOTION IN A PLANE.pdf ✅

(10.) A particle is moving in circle of radius r centered at O with constant speed v . The change in velocity in moving from A to B( AOB 40 = ) is : (1) 2 cos40 v (2) 2vsin40 (3) 2vcos20 (4) 2vsin20 (11.) A particle moves in a circle of radius 25 cm at two revolutions per second. The acceleration of the particle in metre per seond 2 is (1)  (2) 2 8 (3) 2 2 (4) 2 4 (12.) A bucket tied at the end of a 1.6 m long string is whirled in a vertical circle with constant speed. what should be the minimum speed so that water from the bucket does not spill when the bucket is at the hightest position? (take 2 g 10 ms− = ) : (1) 4 m / sec . (2) 6.25 m / sec (3) 16 m / s (4) None of these (13.) Find the maximum velocity with which a train can be moved on a circular track of radius 200 m . the banking of the track is 5.71 and tan5.17 0.1 = : ( ) 2 g = 9.8 m / s (1) 1 1.4 ms− (2) 1 14 ms− (3) 1 140 ms− (4) 1 0.14 ms− (14.) Two particles of equal masses are revolving in circular paths of radii 1 r and 2 r respectively with the same speed. The ratio of their centripetal force is : (1) 2 1 r r (2) 2 1 r r (3) 2 1 2 r r       (4) 2 2 1 r r       (15.) A mass of 100gm is tied to one end of a string 2 m long. The body is revoling in a horizontal circle making a maximum of 200 revolutions per min. The other end of the string is fixed at the centre of the circle of revolution. The maximum tension in the string is. [approximately] (1) 8.76 N (2) 8.94 N (3) 89.42 N (4) 87.64 N (16.) In a vertical circle of radius r , at what point in its path a particle has tension equal to zero (when particle just complete the circle) : (1) Highest point (2) Lowest point