Motion and Measurement of Distances

Q1. Fill in the blanks.

                        i.        Measurement is the comparison of an unknown quantity with some fixed quantity.

                       ii.        1 km = 1000 m.

                      iii.        Standard unit of length is metre.

                      iv.        The length of curved line can be measured using a thread.

                      v.        Length is the distance between two points or ends of an object.

                     vi.        Motion means the change in position of an object with time.

Q2. True/False

                       i.        The choice of device used for the measurement depends on the type of measurement to be made. True

                      ii.        Our senses are reliable for accurate measurement. False

                     iii.        1m = 100cm. True

                     iv.        5km = 5000cm. False

                      v.        Motion of a child on a swing is periodic motion. True

                     vi.        Motion of a wheel of a cycle is random motion. False

Q3. Which measuring device can be used to measure the girth of a tree?

Ans. Measuring tape

Q4. Write the type of motion in which a body moves along a straight path.

Ans. Rectilinear or linear motion

Q5. Which unit of length is used to measure a large distance?

Ans. Kilometre

 
Q6. Write one example of circular motion.

Ans. Motion of hands of a clock

Q7. Write one example of rectilinear motion.

Ans. Motion of an apple falling from a tree

 
Q8. Write one example of periodic motion.

Ans. A bouncing ball

Q9. Name the type of motion in which a body moves along a curved path.

Ans. Circular or Rotational motion

Q10. Name the type of motion in which motion repeats after equal time interval.

Ans. Periodic motion

Q11. The distance between Ria’s house and temple is 1340 m. Express this distance in kilometre.

Ans. 1km = 1000m

       1340/1000 = 1.340 km

 
Q12. Find the length of square in mm.

Ans. Each side = 5 x 10 = 50mm (All sides of square are equal)

Q13. Define ‘unit’.

Ans. The fixed quantity with which we compare an unknown quantity is called unit.

 
Q14. When object is said to be in rest?

Ans. If the position of an object does not change with time, it is said to be at rest.

 
Q15. What do you understand by ‘measurement’?

Ans. Measurement means the comparison of some unknown quantity with a known fixed quantity of same kind.

Q16. What is the common in between hand span, pace, angul and fist?

Ans. All of these are non-standard units of measurement that changes from person to person.

Q17. When object is said to be in motion?

Ans. When an object changes its position with time with respect to another object, it is said to be in motion.

Q18. Why is the hand span not considered as a reliable unit for measuring the length?

Ans. Hand span is not considered as a reliable unit for measuring the length because length of hand span varies from person to person.

Q19. What do you understand by standard unit of measurement?

Ans. The unit which is acceptable to the majority of people as a basic unit of measurement is called standard unit of measurement.