Measurement of distance and <br>motion class 6
Standard unit: the unit that has a fixed value and does not change from place to place or person to person
Periodic motion: a motion that repeats itself after a fixed interval of time measurement: comparing an unknown
Quantity with a known quantity linear motion: motion occurring in a straight line
Oscillation: The movement of the pendulum from the point of origin to the same point circular motion: motion occurring in a circular pattern
Rotation: moving around an axis Wheel showing rolling motion Planets showing uniform motion
Motion: change in position with respect to the surrounding
Metre: a standard unit of length centimetre: a smaller unit of length. One hundredth part of a metre
Uniform motion: motion in which body travels an equal distance in equal intervals of time
Translatory motion: motion in which a body moves as a whole and every point on it moves the same distance. Non-uniform motion: motion in which a body travels unequal distance in equal interval of time.
Curvilinear motion: motion that takes place along a curve
POINTS TO REMEMBER
• A motion which is repeated after fixed intervals of time is periodic.
• The standard unit of length is metre (m)
• The unit which people agree to use as a basic unit of measurement is called a standard unit.
• The length of the footstep, arm (cubit) and hand span cannot be used as standard units of measurement because these vary from person to person.
• A measurement is an act of measuring the dimension of a physical quantity.
• When a body covers unequal distances indefinite intervals of time, its motion is called non-uniform motion.
• Circular or rotational motion of a body takes place in a circle; however, an incomplete circular motion is called
• Length, mass, time and temperature are the basic units of measurement.
• Different modes of transport are used to go from one place to another.
A. Multiple Choice Questions:
1. Which of the following modes of transport is not based on the invention of the wheel?
(d) Bullock cart
2. The unit you will use to measure the distance from Delhi to Patna is
3. To measure the length of a curved line, you will use:
(b) geometry scale
(d) both a and c
4. Which one of the following is the smallest unit of length?
5. Which is an example of rotatory motion?
(a) a planet moving around the sun
(b) a boy on a giant wheel
(c) a spinning top
(d) the bob of a swinging pendulum
6. A ball rolling on a ground shows
(a) periodic motion
(b) rectilinear motion
(c) rotational motion
(d) both (b) and (c)
7. The motion of a pendulum is
8. The motion of the arms of soldiers in a march past is
9. Kelvin is the unit of
10. SI unit of mass is
1. (a) 2. (b) 3. (d) 4. (a) 5. (c) 6. (d) 7. (a) 8. (c) 9. (d) 10. (d)
B. Fill in the blanks
1. Accurate measurement of any——— is very essential.
2. Motion in a————- is called rectilinear motion.
3. A body moving along a curve is said to be in———– motion.
4. The motion which repeats itself after regular interval of time is called————-.
5. Small and————- are called vibrations.
1. Accurate measurement of an object is very essential.
2. Motion in a straight line is called rectilinear motion.
3. A body moving along a curve is said to be in curvilinear motion.
4. The motion which repeats itself after regular interval of time is called periodic motion.
5. Small and rapid oscillations are called vibrations.
C. State whether ‘True’ or ‘False’
1. The motion of the earth is periodic.
2. The motion of a train along the track is mostly rectilinear and at time curvilinear.
3. Handspan cannot be used to measure length accurately.
4. Mass is a unit of temperature
5. When a screw is tightened it exhibits only rotatory motion.
6. Movements of a bird in the sky can be said to be oscillatory.
1. True, 2. True, 3. True, 4. False, 5. True, 6. True