In which of the following cases the centre of mass of a rod is certainly not at its centre?

Monjur Alahi

In which of the following cases the centre of mass of a rod is certainly not at its centre? 

(a) The density continuously increases from left to right 

(b) The density continuously decreases from left to right 

(c) The density decreases from left to right upto the centre and then increases. 

(d) The density increases from left to right upto the centre and then decreases.


0 like 0 dislike
1 views
Share with your friends

1 Answers

Salim Ahmed Kawsar

Call

(a) The density continuously increases from left to right
(b) The density continuously decreases from left to right

Explanation: 

Assume the parts of the rod on left and right from the middle as two separate bodies. Due to the continuous variation of the density, the masses of each body will be different. The CoM of the lighter body will be closer than that of the heavier body. If we take the middle of the rod as origin then CoM of the rod will be the CoM of these two bodies taking their masses at their CoM, Now Σmx for the heavier part will be greater than the lighter part. Hence total Σmx will not be zero and the CoM of the rod will not be in the middle.

0 like 0 dislike
1 views
Talk Doctor Online in Bissoy App
When a glass rod is rubbed with a piece of silk cloth the rod a. and the cloth both acquire positive charge.

(b). becomes positively charged while the cloth has a negative charge.

1 Answers 1 views
Which of the following is not applicable to responsibility accounting? (a) Investment centre (b) Accounting centre

(b) Accounting centre is not a part of responsibility accounting. Responsibility accounting basically refers to a system in which different divisions of the organisation are established as responsibility centres. Herein, each...

1 Answers 1 views
One end of a uniform rod of mass m and length l is clamped. The rod lies on a smooth horizontal surface and rotates

(d)1/2 mw2l. Explanation:  Since the rod rotates on the horizontal surface, the horizontal component of the force applied by the clamp is the centripetal force = mω²r = mω²(l/2) = ½mω²l.

1 Answers 1 views
A heavy uniform rod is hanging vertically from a fixed support. It is stretched by its own weight. The diameter of the rod is

(a) smallest at the top and gradually increases down the rod Explanation:  For a hanged heavy uniform rod, at any cross-section, the load is only of the part of the rod which...

1 Answers 1 views
Assertion : The image formed by a concave mirror is certainly real if the object is virtual.

(c) The image of real object may be real in case of concave mirror

1 Answers 2 views
An experimenter measures the length of a rod. Initially the experimenter and the rod are at rest with respect to the lab.

(c) Both A and B are true

1 Answers 1 views
An experimenter measures the length of a rod. In the cases listed, all motions are with respect to the lab and parallel to the length of the rod.

(b) The rod and the experimenter move with the same speed v in opposite directions.

1 Answers 1 views
When a rod moves at a relativistic speed v, its mass (a) must incrase by a factor of γ

(a) must incrase by a factor of γ

1 Answers 1 views
Assertion (A): Battle of Khanua was certainly more decisive and significant than the First Battle of Panipat Reason (R):

(a) Battle of Khanua (1527, Rana Sanga was defeated by Babar); First Battle of Panipat (1526, Ibrahim Lodhi was defeated by Babur). Rana Sangha once defeated Ibrahim Lodhi so R...

1 Answers 2 views
When iron rod is kept dipped in copper sulphate solution for some time, a brown coating is formed on the iron rod.

Blue colour of the solution changes to light green. Reddish brown deposit is formed on the iron nail. Fe(s) + CuSO4(aq) → FeSO4(aq) + Cu(s)

1 Answers 2 views
X