Two masses M and M/2 are joined together by means of light inextensible string passed over a frictionless pulley as shown in the figure. When the bigger mass is released, the small one will ascend with an acceleration of
g
In elastic collision
both momentum and kinetic energies are conserved
both momentum and kinetic energies are not conserved
only energy is conserved
only mechanical energy is conserved
Three identical spheres, each ofmass 1 kg are kept as shown in figure below, touching each other, with their centres on a straight line. If their centres are marked P, Q, R respectively, the distance of centre of mass of the system from P is
The moment of inertia of a thin rod of mass M and length L, about an axis perpendicularto the rod at a distance from one end is
A body rolls down an inclined plane. If its kinetic energy of rotation is 40% of its kinetic energy of translation, then the body is
solid cylinder
solid sphere
disc
ring
Which of the following statements about the gravitational constant is true ?
It is a force
It has no unit
It has same value in all systems of units
It does not depend on the nature of the medium in which the bodies are kept
Two identical solid copper spheres of radius R are placed in contact with each other. The gravitational attraction between them is proportional to
R2
R-2
R4
R-4
C.
R4
A piece of ice is floating in a jar containing water. When the ice melts, then the level of water
rises
falls
remains unchanged
rises or falls
A wire of length L and area of cross-section A is stretched through a distance x metre by applying a force F along length, then the work done in this process is (Y is Young's modulus of the material)
An ice box made of Styrofoam (Thermal conductivity = 0.01Jm-1 s-1 K-1 ) is used to keep liquids cool. It has a total wall area including lid of 0.8 m and wall thickness of 2.0 cm. A bottle of water is placed in the box and filled with ice. If the outside temperature is 30°C the rate of flow of heat into the box is (in J-s-1 )
16
14
12
10