Stress: It is defined as the force applied on unit area to produce change in the shape,volume or length of a body.Mathematically it is expressed as: The SI unit of stress (σ) is newton per square meter (Nm-2),which is given the name pascal  (pa). Stress may cause a change in length,volume and shape. Tensile stress: When a stress  changes the ...

Angle between two vectors: The angle between two vectors a and b is determined from the definition of dot product,that is: If θ = 0 or π   then the vectors a and b are collinear. If  θ = 90 then the vectors a and b will be perpendicular to each other. Example:Find the angle between the vectors. a = 2 i –j ...

What is a vector ? Types of vectors Vectors scalar product Vector cross product How to find angle between two vectors? Vectors,both in plane and in space have following properties: Let u ,v and w be vectors in the plane or in space and let a,b ∈ R then they have the following properties: Commutative property u + v = v ...

Difference between vector and scalar Vector scalar or Dot product Vector cross product Properties of vectors How to find angle between vectors? Types of vector What is vector in physics? Vector is defined as”The physical quantity which has magnitude and direction is called vector.”There are some physical quantities which required magnitude as well as direction for their complete description,such as ...

Electric potential: “Electric potential at a point in electric field is the amount of work done to bring the unit positive charge from infinity to that point.” The gravitational potential at point in the gravitational field is the gravitational potential energy of a unit mass placed at that point.In this way ,the electric potential at any point in the electric ...

Centripetal force: “The force which is directed towards the centre of circle is called centripetal force.” Explanation: Consider a body moving with uniform speed in a circular path.In this case velocity changes only in direction and not in magnitude.Applying Newton’s first law of motion we find that some external force must be acting on the particle.Without presence of external force ...

Unfortunately,weight and mass are often considered to be same quantities and misused in daily conversations.It is therefore essential for you to differentiate between these two physical quantities. Weight and mass difference: Properties of mass: Mass is the quantity of matter possessed by a body. It is a scalar quantity,which has magnitude only. Its unit is kilogram (kg). It is not ...

What is gravitational acceleration? Acceleration of a freely falling bodies is called gravitational acceleration.The value of gravitational acceleration is 10 ms-².   Why value of g varies with altitude? Above formula shows that the value of acceleration due to gravity g depends on the radius of the earth at its surface.The value of g is inversely  proportional to the square ...

What does law of conservation of energy mean? According to law of conservation of energy:”Energy can neither be created nor is it destroyed.It can only be transformed from one form to another.A loss in one form of energy is accompanied by an equal increase in the other forms of energy.The total energy remains constant.” According to Einstein’s mass energy relation: ...

Definition of motion in physics: “A body is said to be in motion,if it changes its position with respect to its surroundings.” Surroundings are the places in its neighborhood where various objects are present.The state of rest or motion of a body is relative.For example,a passenger sitting in a moving bus is at rest because he is not changing his ...