Lab Manual: Velocity of a Pulse in Slinky | Lab Manuals for Class 9 PDF Download

Objective

Theory

• Wave: A wave is a disturbance that moves through a medium when the particles of the medium set neighbouring particles into motion by transfer of energy.
• Slinky: A slinky is a long spring which is flexible and has appreciable elasticity.
• Pulse: A wave produced by a single disturbance in a medium is known as pulse.
  Velocity of pulse = Total distance travelled by pulse / Total time taken

Materials Required

Procedure

• Mark a point on the floor of a long corridor. Let this point be P.
  
• From point P measure the distance of 1 m with the help of metre scale, mark this point as Q.
• Allow one student to hold one end of slinky at point P.
• Let another student stretch the slinky and bring it at point Q.
• Let third student hold the stopwatch.
• The student who has stretched the slinky will stretch it beyond point Q and then give a sharp push towards pointQ. The push should stop at point Q.
• A pulse is produced in the slinky which travels towards the point P and it gets reflected backtowards point Q.
• Record the time from push at Q to the pulse travelling towards P and back at Q.
• Follow the above procedure 56 times and record your observation
• Calculate the velocity of pulse by the formula
  Velocity of pulse = Total distance travelled by pulse / Total time taken
  v = 2d/t

Observation Table

Average velocity of pulse = 0.176 + 0.198 + 0.189 + 0.174 + 0184 / 5 = 0.1842

Result

• Slinky used should be of good quality and with even springs coiled all over.
• Accurately measure the distance and time.
• The push at the end should be forceful to see the pulse and get the reflected wave back.
• The slinky should not have any knot or kink at any point along its length.