CBSE
Multiple Choice QuestionsA rod PQ of mass M and length L is hinged at end P. The rod is kept horizontal by a massless string tied to point Q as shown in figure. When string is cut, the initial angular acceleration of the rod is
A solid uniform sphere resting on a rough horizontal plane is given a horizontal impulse directed through its centre so that it starts sliding with an initial velocity v0. When it finally starts rolling without slipping the speed of its centre is
An explosion breaks a rock into three parts in a horizontal plane. Two of them go off at right angles to each other. The first part of mass 1 kg moves with a speed of 12 ms-1 and the second part of mass 2 kg moves with 8 ms-1 speed. If the third part flies off with 4 ms-1 speed, then its mass is
3 kg
5 kg
7 kg
17 kg
Short Answer TypeAn infinite number of charges, each equal to q, are placed along the x-axis at x=1, x=2, x = 4, x=8 and so on. What is the potential at x = 0 due to this set of charges ?
Multiple Choice QuestionsTwo particles A and B are moving as shown in the figure.
Their total angular momentum about the point O is
9.8 kg m2 / s
zero
52.7 kg m2 / s
37.9 kg m2 / s
A circular disc rolls on a horizontal floor without slipping and the centre of the disc moves with a uniform velocity v. Which of the following values of the velocity at a point on the rim of the disc can have ?
v
− v
2v
Zero
A large number of particles are placed around the origin, each at a distance R from the origin. The distance of the centre of mass of the system from the origin is
equal to R
less than equal to R
greater than R
greater than equal to R
Three identical square plates rotate about the axes shown in the figure in such a way that their kinetic energies are equal. Each of the rotation axes passes through the centre of the square. Then the ratio of angular speeds ω1 : ω2 : ω3 is
1 : 1 : 1
