Class 7 Chapter 13 Science Motion and Time Notes (NCERT)

Class 7 Chapter 13 Science Motion and Time Notes (NCERT) to make the chapter easier. I hope it helps you.

1. 1) Motion-> The moving of objects with respect to time
and space.
2) Speed-> The distance covered in a unit of time.
3) Distance-> The total area covered by a moving object.
4) Displacement-> Minimum distance between two points.
5) Rest-> When there is no change in the position with
respect to time and space.
6) Amplitude-> The maximum displacement of an object
from its mean position.
7) Time period-> Time taken by a pendulum to complete
one oscillation.
Time taken
No. of oscillations
.
8) Oscillation-> Movement of pendulum from B to A, A to
C and then back to B.





9)
10) Full moon to next full moon-> Month, One sunrise
to next sunrise-> Day
Position A
Position B
Position C
Bob- A small metallic ball in
the pendulum which is
suspended from a rigid
stand by thread

2. 11) Unit of time-> Seconds, Unit of speed-> m/s, Unit
of distance-> metre. All units should be written in
singular.
12) Galileo Galilei (1564-1642) discovered that the time
period of a pendulum remains constant. He was once at
a church and saw that the pendulum there had a time
period same as his pulse rate and found by
experimenting that pendulum always take the same
time for every oscillation. The time period of pendulum
depends on->
a. Oscillation speed
b. Weight of bob
13) Microsecond-> 0.000001 second or millionth of a
second, Nanosecond-> 0.000000001 second or billionth
of a second.

14)





15) Types of clocks in medieval ages->
a. Sundial-> shows shadows from the sun and tells
the time.
b. Sand clock-> acts as a stopwatch for a particular
time.
c. Water clock

3. 16) Speedometer-> The part in dashboard of a car
which tells the speed of the car.
17) Odometer-> The part in car which tells the total
distance travelled by the car.
18) Graph-> Graphical representation of any collection
of value.
19) We can quickly derive information from graphs.
Features of experimental data can be seen visually.
20) We should always utilize the size of paper on which
we are making graphs, because it helps in choosing the
scale efficiently. Always know the scale accurately and
the difference between the 1
st
and last observation.