← Back to the activity

Year 8 Science — Measuring time

Say how old clocks kept time, find a pendulum's time period from a count of oscillations, and convert between the second, the minute and the hour.

Name: ________________________

Before you start

The parts of a simple pendulum, and where the bob reaches at one extreme.

1234
  1. 1. The support
  2. 2. The thread
  3. 3. The bob
  4. 4. One extreme

The dark bob hangs at the mean position, straight below the support. The pale one shows where it reaches at one extreme; there is a matching extreme on the other side. One oscillation is mean, extreme, across to the other extreme, back to mean.

  1. 1.What does a quartz clock count to keep time?

    • a) Drops of water falling through a fine hole
    • b) The turning of gears driven by a hanging weight
    • c) The swings of a very short pendulum
    • d) Very rapid vibrations of a quartz crystal

  2. 2.Which of these is written correctly, following the chapter's rules for units of time?

    • a) 30sec
    • b) 30 s
    • c) 30 Sec
    • d) 30S

  3. 3.A song lasts 4 minutes. How many seconds is that? Answer with a number.

  4. 4.A journey takes 6 hours. How many minutes is that? Answer with a number.

  5. 5.The bowl of a Ghatika-yantra was holed so that it took 24 minutes to fill and sink. Into how many of those intervals was a day divided?

    • a) 24
    • b) 60
    • c) 100
    • d) 12

  6. 6.A pendulum takes 20 seconds to complete 10 oscillations. What is its time period, in seconds? Answer with a number.

  7. 7.The time a pendulum takes to complete one oscillation has a two-word name. What is it?

  8. 8.What is the SI unit of time? Give the word, not the symbol.

Answer key — Year 8 Science — Measuring time

  1. 1. d) Very rapid vibrations of a quartz crystal
  2. 2. b) 30 s
  3. 3. 240
  4. 4. 360
  5. 5. b) 60
  6. 6. 2
  7. 7.
    • time period
    • the time period
  8. 8. second