Sign up now
to enroll in courses, follow best educators, interact with the community and track your progress.
Download
Introduction to Kinematics (in Hindi)
16,306 plays

More
Introduction to position vector, distance, displacement with a problem.

Udit Gupta is teaching live on Unacademy Plus

Udit Gupta
A Mechanical Engineer from NIT Allahabad here to help learners with physics. Also a Star ⭐ educator.

U
Unacademy user
Ma'am is it sufficient for mains exam if I make notes from your lecture
sir it will help me in iit jee
sir I'm confused after doing this course and then ur motion in two dimension course.,we can do complete kinematics of HC Verma?..I mean it covers all that projectile relative and all?? please reply sir...
Ak
sir aap live kab hote ho
MS
sir I think ans of problem 2 b displacement..have some mistake
Udit Gupta
3 months ago
Let's peace out on answer and focus on the approach.. Is thag clear?
sir i thik in 2nd problem, part (a) have mistake of 0.8
Udit Gupta
3 months ago
I don't think so... Even if it is there I hope you understood the process and calculations would take care of hopefully.. Hope this is helpful
  1. Motion in 1D - 1 Compiled by: Udit Gupta Alumnus MNNIT Allahabad Ex-Manager at Reliance Industries Limited Ex-VidyaMandir Faculty of Physics Cofounder and HOD Physics Elements Azamgarh


  2. Content Introduction Position Displacement . Distance Problems on displacement and distance


  3. Introduction . This is the topic where we start mechanics In vectors we learnt how to deal with those quantities and now we will see their application. Mechanics is broadly divided in two topics namely kinematics and dynamics. In kinematics we deal with the motion of the particle (position, displacement, velocity and acceleration) not concerned with the factors producing that motion.


  4. Position It refers to the location of a particle in space at a certain moment of time. Generally, this position is measured by a vector called position vector r) which is a line joining origin (fixed point) to the position of the particle.


  5. Displacement . It is a vector joining initial position to the final position of a particle during a certain interval of time. We can simply say that the change in position of a moving particle is its displacement (s)


  6. Distance It is the length of the actual path traversed by a particle. We can simply call it the length of path travelled by the particle. It is generally denoted by s or x.


  7. Problem 1 An old person moves on a semi-circular track of radius 40.0m during a morning walk. If he starts at one end of the track and reaches at the other end, find the distance covered and the displacement of the person.


  8. Problem 1 . Distance = length of track = x 40.0m = 126m . Displacement-diameter of the semi-circular track = 2r = 80m 40m


  9. Problem- 2 A table clock has its seconds hand 4.0 cm long. Find the displacement and the distance of the tip of the seconds hand: (a) 30 seconds apart (b) 150 seconds apart.


  10. Problem- 2 (a) In 30 seconds, the tip of seconds hand moves diametrically to the opposite side. Displacement = 8.0 cm Distance = (4) = 4 cm (b) In 150 seconds, the displacement is still the same but distance increases. Distance = 2(2 (4)) + (4) = 20