One end of string of length $$l$$ is connected to a particle of mass 'm' and the other end is connected to a small peg on a smooth horizontal table. If the particle moves in circle with speed '$$\upsilon $$', the net force on the particle (directed towards centre) will be (T represents the tension in the string)
A
$$T + {{m{v^2}} \over l}$$
B
$$T - {{m{v^2}} \over l}$$
C
zero
D
$$T$$
2
NEET 2016 Phase 1
MCQ (Single Correct Answer)
+4
-1
A car is negotiating a curved road of radius R. The road is banked at an angle $$\theta $$. The coefficient of friction between the tyres of the car and the road is $$\mu $$s. The maximum safe velocity on this road is
Two stones of masses m and 2m are whirled in horizontal circles, the heavier one in a radius $${r \over 2}$$ and the lighter one in radius r. The tangential speed of lighter stone is n times that of the value of heavier stone when they exprience same centripetal forces. The value of n is
A
4
B
1
C
2
D
3
4
AIPMT 2015
MCQ (Single Correct Answer)
+4
-1
A plank with a box on it at one end is gradually raised about the other end. As the angle of inclination with the horizontal reaches 30o, the box starts to slip and slides 4.0 m down the plank in 4.0 s.
The coefficients of static and kinetic friction between the box and the plank will be, respectively
