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1
JEE Main 2021 (Online) 17th March Evening Shift
+4
-1
A sphere of mass 2 kg and radius 0.5 m is rolling with an initial speed of 1 ms-1 goes up an inclined plane which makes an angle of 30$$^\circ$$ with the horizontal plane, without slipping. How long will the sphere take to return to the starting point A? A
0.60 s
B
0.52 s
C
0.80 s
D
0.57 s
2
JEE Main 2021 (Online) 17th March Morning Shift
+4
-1
A mass M hangs on a massless rod of length l which rotates at a constant angular frequency. The mass M moves with steady speed in a circular path of constant radius. Assume that the system is in steady circular motion with constant angular velocity $$\omega$$. The angular momentum of M about point A is LA which lies in the positive z direction and the angular momentum of M about point B is LB. The correct statement for this system is : A
LA is constant, both in magnitude and direction
B
LB is constant in direction with varying magnitude
C
LB is constant, both in magnitude and direction
D
LA and LB are both constant in magnitude and direction
3
JEE Main 2021 (Online) 16th March Morning Shift
+4
-1
A block of 200 g mass moves with a uniform speed in a horizontal circular groove, with vertical side walls of radius 20 cm. If the block takes 40 s to complete one round, the normal force by the side walls of the groove is :
A
9.859 $$\times$$ 10$$-$$2 N
B
0.0314 N
C
9.859 $$\times$$ 10$$-$$4 N
D
6.28 $$\times$$ 10$$-$$3 N
4
JEE Main 2021 (Online) 16th March Morning Shift
The maximum and minimum distances of a comet from the Sun are 1.6 $$\times$$ 1012 m and 8.0 $$\times$$ 1010 m respectively. If the speed of the comet at the nearest point is 6 $$\times$$ 104 ms$$-$$1, the speed at the farthest point is :
3.0 $$\times$$ 103 m/s
6.0 $$\times$$ 103 m/s
1.5 $$\times$$ 103 m/s
4.5 $$\times$$ 103 m/s