1
AIPMT 2014
+4
-1
A balloon with mass m is descending down with an acceleration a (where a < g). How much mass should be removed from it so that it starts moving up with an acceleration a ?
A
$${{2ma} \over {g + a}}$$
B
$${{2ma} \over {g - a}}$$
C
$${{ma} \over {g + a}}$$
D
$${{ma} \over {g - a}}$$
2
AIPMT 2014
+4
-1
A system consists of three masses m1, m2 and m3 connected by a string passing over a pulley P. The mass m1 hangs freely and m2 and m3 are on a rough horizontal table (the coefficient of friction = $$\mu$$). The pulley is frictionless and of negligible mass. The downward acceleration of mass m1 is (Assume m1 = m2 = m3 = m)

A
$${{g\left( {1 - g\mu } \right)} \over 9}$$
B
$${{2g\mu } \over 3}$$
C
$${{g\left( {1 - 2\mu } \right)} \over 3}$$
D
$${{g\left( {1 - 2\mu } \right)} \over 2}$$
3
NEET 2013 (Karnataka)
+4
-1
A car is moving in a circular horizontal track of radius 10 m with a constant speed of 10 m/s. A bob is suspended from the roof of the car by a light wire of length 1.0 m. The angle made by the wire with the vertical is
A
$${\pi \over 3}$$
B
$${\pi \over 6}$$
C
$${\pi \over 4}$$
D
0o
4
NEET 2013
+4
-1
The upper half of an inclined plane of inclination $$\theta$$ is perfectly smooth while lower half is rough. A block starting from rest at the top of the plane will again come to rest at the bottom, if the coefficient of friction between the block and lower half of the plane is given by
A
$$\mu$$ = 2 tan$$\theta$$
B
$$\mu$$ = tan$$\theta$$
C
$$\mu$$ = $${1 \over {\tan \theta }}$$
D
$$\mu = {2 \over {\tan \theta }}$$
EXAM MAP
Medical
NEET