Advertisements
Advertisements
प्रश्न
Which of the following points is the likely position of the centre of mass of the system shown in figure?
पर्याय
A
B
C
D
उत्तर
C
Explanation:
The centre of mass of a system lies towards the part of the system, that has a bigger mass. In the above diagram, the lower part is heavier, hence CM of the system lies below the horizontal diameter.
APPEARS IN
संबंधित प्रश्न
The centre of mass is defined as \[\vec{R} = \frac{1}{M} \sum_i m_i \vec{r_i}\]. Suppose we define "centre of charge" as \[\vec{R}_c = \frac{1}{Q} \sum_i q_i \vec{r_i}\] where qi represents the ith charge placed at \[\vec{r}_i\] and Q is the total charge of the system.
(a) Can the centre of charge of a two-charge system be outside the line segment joining the charges?
(b) If all the charges of a system are in X-Y plane, is it necessary that the centre of charge be in X-Y plane?
(c) If all the charges of a system lie in a cube, is it necessary that the centre of charge be in the cube?
Calculate the velocity of the centre of mass of the system of particles shown in figure.
A block of mass 2.0 kg moving 2.0 m/s collides head on with another block of equal mass kept at rest. (a) Find the maximum possible loss in kinetic energy due to the collision. (b) If he actual loss in kinetic energy is half of this maximum, find the coefficient of restitution.
Define centre of mass.
A bullet of mass 20 gram is fired from a gun of mass 2.5 kg with a speed of 750 m/s. The magnitude of recoil velocity of the gun is ______.
A shell of mass 'M' initially at rest suddenly explodes in three fragments. Two of these fragments are of mass 'M/4' each, which move with velocities 3 ms-1 and 4 ms-1 respectively in mutually perpendicular directions. The magnitude of velocity of the third fragment is ______.
For which of the following does the centre of mass lie outside the body?
A uniform square plate has a small piece Q of an irregular shape removed and glued to the centre of the plate leaving a hole behind figure. The CM of the plate is now in the following quadrant of x-y plane ______.
Figure shows a lamina in x-y plane. Two axes z and z ′ pass perpendicular to its plane. A force F acts in the plane of lamina at point P as shown. Which of the following are true? (The point P is closer to z′-axis than the z-axis.)
- Torque τ caused by F about z axis is along `-hatk`.
- Torque τ′ caused by F about z′ axis is along `-hatk`.
- Torque τ caused by F about z axis is greater in magnitude than that about z axis.
- Total torque is given be τ = τ + τ′.
Find the centre of mass of a uniform (a) half-disc, (b) quarter-disc.
