Motion in a plane NEET

Law of motion Force Basic (lec 1)

 video lectures for Force Basic


Question 1: Define the `S.I.` unit of force.

a) Joule

b) KG

c) KW

d) Newton


Question 2: What is meant by an unbalanced force?


Question 3: Define force field.
 

Question 4:Define viscous force.
 

Question 5: State Hooke’s Law.


Question 6: Name the force which is responsible for circular motion.


Question 7: What are lubricants?



Question 8: Identify all forces that are acting on the objects described below. 
(a) A block placed on a rough inclined surface. 
(b) A person standing on a horizontal surface
(c) The bob of a simple pendulum when it is at one extreme end while oscillating about its mean position.


Answer Key

Q1. (d),
Q2. When the resultant force acting on a body is not equal to zero, the forces acting on the body are known as unbalanced forces.
Q3. A force field is an area of energy, such as magnetic energy, that surrounds an object or place.
Q4. It is the resistance (internal) force provided by a fluid when it is subjected to tangential force on its surface (shear).
Q5.  Hooke's law states that the applied force `F` equals a constant `k` times the displacement or change in length `x`, or `F` = `kx`.
Q6.  Centripetal force
Q7. A substance (such as grease) capable of reducing friction, heat, and wear when introduced as a film between solid surfaces.
Q8. (a)  Three forces act on a body placed on a rough inclined plane. 
 (i) Weight in the downward direction. 
 (ii)  Normal force which is perpendicular to the surface on which it is placed. 
 (iii) frictional force as shown in the figure.



(b) (i)  weight of the person is in the downward direction. 
(ii)  Normal reaction force in the upward direction. 
(iii)  Frictional force in a direction opposite to his motion. 

(c) Two forces act on the bob. One is weight of the bob acting downward and the other is tension along the string.


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