National Science Olympiad Forum By SOF Olympiad Trainer - Page 112

User Forum

Subject :NSO    Class : Class 8

Post Your Answer

Subject :NSO    Class : Class 8

Which of the following statements is/are correct?
(A) To increase the stability of a ship the base area must be made large.
(B) A cone which is resting on its apex is an example of unstable equilibrium.
(C) The momentum of a body is the product of mass and velocity of the body.
(D) Frictional force always acts in a direction opposite to the direction of motion.

A(A) and (B)
B(A), (B) and (C)
C(B) and (C)
DAll of these


Frictional force acts relativly opposite to the direction of motion Isnt the answer B then ?

Ans 1:

Class : Class 8
In my opinion, the answer to this question should be option (B), instead of option (D). According to option (D), the statement - (D), is correct. However, it is not nearly correct. Frictional force doesn't always act in a direction opposite to the direction of motion. There are many exceptions to this case. For example: A car's wheels turning to push back on the road experiences a forward friction that helps it move, a person's leg pushing back on the pavement experiences a forward friction that helps him/her to walk, etc. Thus, relative to a fixed point, friction can also help to support overall motion. So, statement (D) is incorrect. The statement: "Frictional force always acts in a direction opposite to the direction of 'relative' motion." would be more correct, as from the fixed point of motion, friction will always oppose the relative motion of a body.

Post Your Answer

Subject :NSO    Class : Class 6

Ans 1:

Class : Class 8
Earth will be B

Post Your Answer

Subject :NSO    Class : Class 8

Post Your Answer

Subject :NSO    Class : Class 7

Read the given passage. There are 3 types of blood cells, X, Y and Z. X is biconcave disc shaped and contains haemoglobin. Y protects us from many diseases and helps fight infection. Z helps in blood clotting. Select the incorrect option regarding X, Y and Z.

APeople living in higher altitudes have higher X count as compared to people living in plains.
BHigh Y count indicates some infection in the body.
CDecrease in Z count also indicates infections like dengue.
DPeople with very low X count continue to bleed even from minor injury as their blood does not clot.


Post Your Answer

Subject :NSO    Class : Class 3

Ans 1:

Class : Class 3

Ans 2:

Class : Class 4

Post Your Answer

Subject :NSO    Class : Class 5

Post Your Answer

Subject :NSO    Class : Class 6

Post Your Answer

Subject :NSO    Class : Class 6

Post Your Answer

Subject :NSO    Class : Class 6

Ans 1:

Class : Class 8
Got It thank you sof

Post Your Answer