CBSE Notes for Class 7 Science Chapter 13 – Motion and Time

Important Notes for CBSE Class 7 Science Chapter 13 – Motion and Time. Motion and Time Class 7 Notes and Study Material Download in PDF form.

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Motion and Time Class 7 Notes 

 Motion can either be in a straight line or circular motion or it may also have periodic motion.

 An object can have either slow motion or may have a fast motion.

 To understand if an object is moving slowly or fast the distance and time is used.

  • SPEED:

1.) Speed of an object is determined by distance and time.

2.) Average speed is usually calculated using total distance covered divided by the total time.

3.) Non- uniform motion: if motion along the same line keeps changing it is called as non-uniform motion

4.) Uniform motion: if the objects move in a straight line, it is called as uniform motion.

Measurement of time:

  • In olden time, time was calculated with the position of the from sunrise to sunset.
  • Time between 2 consecutive sun rises is called a day.
  • A month is a period between one new moon to the next.
  • A year is calculated as the time taken by the art to complete one revolution around the sun
  • Watches, clocks make use of periodic motion to calculate the time. e.g., simple pendulums.
  • Simple pendulum: It is made up of a metallic ball or stone attached to a thread.
  • Bob: it is a metal ball in a pendulum.
  • The pendulum is example of oscillatory or periodic motion.
  • Time period: The time taken to complete one oscillation.

 UNIT OF TIME AND SPEED:

1.) Time is measured in seconds, minutes and hours

2.) The unit of speed is meter per minute or kilometer per hour.

3.) Unit is always measured as a singular unit.

4.) Sundials, water clocks and sand clocks are also used.

 MEASURING SPEED:

  • The speed of an object, you can find the distance moved by it in a unit time.
  • Speedometer is used to measure speed.
  • Odometer is used to measure speed of vehicles.

 DISTANCE-TIME GRAPH:

  • A bar graph, pie chart, line graph can be used to describe distance-time graph.
  • Graph can be drawn on graph paper or on a computer.
  • This graph provides information about the type of motion.

Motion and Time Class 7 Notes PDF

Motion and Time
Updated: October 30, 2021 — 1:41 pm

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