Chapter 10: Motion and Measurement of Distances

Science

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  Chapter 10: Motion and Measurement of Distances

  Class: VI

  Exemplar Solutions

  Multiple Choice Questions

Question 1

The distance between Delhi and Mumbai is usually expressed in units of

 

(a) decameter

(b) meter

(c) centimeter

(d) kilometer

Answer

(d)

 

Question 2

Which of the following does not express a time interval?

 

(a) A day

(b) A second

(c) A school period

(d) Time of the first bell in the school

Answer

(d)

 

Question 3

Fig. 10.1 shows a measuring scale which is usually supplied with a geometry box. Which of the following distance cannot be measured with this scale by using it only once?

 

 

Fig. 10.1

 

(a) 0.1 m

(b) 0.15 m

(c) 0.2 m

(d) 0.05 m

 

Answer

 

(c)

 

Question 4

 

A piece of ribbon folded five times is placed along a 30 cm long

measuring scale as shown in Fig. 10.2.

 

 

Fig.10.2

 

The length of the ribbon is between

(a) 1.15 m - 1.25 m

(b) 1.25 m - 1.35 m

(c) 1.50 m - 1.60 m

(d) 1.60 m - 1.70 m

 

Answer

 

(b)

 

Question 5

 

Paheli moves on a straight road from point A to point C. She takes 20 minutes to cover a certain distance AB and 30 minutes to cover the rest of distance BC. She then turns back and

takes 30 minutes to cover the distance CB and 20 minutes to cover the rest of the distance to her starting point. She makes 5 rounds on the road the same way. Paheli concludes that her motion is

(a) only rectilinear motion.

(b) only periodic motion.

(c) rectilinear and periodic both.

(d) neither rectilinear nor periodic.

 

Answer

(c)

 

Question 6

 

Bholu and Golu are playing in a ground. They start running from the same point A in the ground and reach point B at the same time by following the paths marked 1 and 2 respectively as shown in Fig. 10.3. Which of the following is/are true for the given situation.

 

 

Fig.10.3

 

As compared to Golu, Bholu covers a

(a) longer distance but with a lower speed.

(b) longer distance with a higher speed.

(c) shorter distance with a lower speed.

(d) shorter distance with a higher speed.

 

Answer

 

(b)

 

Question 7

 

Four pieces of wooden sticks A,B,C and D are placed along the length of 30 cm long scale as shown in Fig. 10.4. Which one of them is 3.4 cm in length?

 

 

Fig.10.4

 

(a) A

(b) B

(c) C

(d) D

Answer

 

(c)

 

Question 8

 

Which of the following figure shows the correct placement of a block along a scale for measuring its length?

 

 

 

 

 

(a) 

 

 

 

 

 

 

 

 

 

(b) 

 

 

 

 

 

 

 

 

 

(c) 

 

 

 

 

 

 

 

 

 

(d) 

 

  Fig.10.5

 

Answer

 

(b)

 

Question 9

 

You are provided three scales A, B and C as shown in Fig. 10.6 to measure a length of 10 cm.

 

 

 

A

 

 

B

 

 

 

 

 

 

 

 

C

 

Fig.10.6

 

 

For the correct measurement of the length you will use the scale

 

(a) A only   (b) B only.

(c) C only  (d) Any of the three scales.

 

Answer

 

(d)

 

 

Very Short Answer Questions

 

Question 10

 

Correct the following.

(i) The motion of a swing is an example of rectilinear motion.

(ii) 1m = 1000 cm

 

Answer

 

(i) The motion of a swing is an example of periodic motion.

  or

The motion of a swing is not an example of rectilinear motion.

 

(ii) 1m = 100 cm

 

 

Question 11

 

Fill in the blanks

 

(i) Motion of an object or a part of it around a fixed point is known as ................ motion.

(ii) A body repeating its motion after certain interval of time is in  ......... motion.

(iii) In rectilinear motion, object moves........... a .......... line.

(iv) SI unit of length is ..........

 

Answer

 

(i)  circular

(ii)  periodic

(iii) straight; along

(iv)  meter

 

Question 12

 

Write one example for each of the following type of motion.

 

(i)  Rectilinear

(ii)  Circular

(iii) Periodic

(iv) Circular and periodic

 

Answer

 

(i) An object moving on a straight road, falling stone, etc.

(ii) A mark on blades of a rotating fan, tips of the hands of a clock, etc.

(iii) Motion of a child on a swing, motion of pendulum, strings of a guitar, etc.

(iv) Blades of a rotating fan, hands of a clock, etc.

 

 

Short Answer Questions

 

Question 13

 

 

Fig.10.7

 

The photograph given as Fig. 10.7 shows a section of a grille made up of straight and curved iron bars. How would you measure the length of the bars of this section, so that the payment could be made to the contractor?

Answer

 

The length can be measured using a thread which can be further measured with the help of a scale.

 

Question 14

 

Identify the different types of motion in the following word diagram given as Fig. 10.8.

 

 

Fig.10.8

 

Answer

 

 

 

 

Question 15

 

Four children measure the length of a table which was about 2 m. Each of them used different ways to measure it.

 

(i) Sam measured it with a half metre long thread.

(ii) Gurmeet measured it with a 15 cm scale from her geometry box.

(iii) Reena measured it using her hand span.

(iv) Salim measured it using a 5 m long measuring tape.

 

Which one of them would get the most accurate length? Give reason for your answer.

 

Answer

 

Salim would get the most accurate length. The reason is that in this case the length of the table can be measured in one go because the measuring tape is longer than the table. In the other cases the chance of making an error is higher due to multiple measurement. In case of Sam, he can measure the lengths which are exact multiples of half a meter.

 

Question 16

 

Match the events related to motion in Column I with the types of motions given in Column II.

 

 

 

 

 

 

Answer

 

a– (ii);  b– (i);  c– (iii).

 

 

Long Answer Questions

 

Question 17

 

While travelling in a train, it appears that the trees near the track are moving whereas co-passengers appear to be stationary. Explain the reason.

 

Answer

 

When we see the trees from a moving train, their position is changing with respect to us. Hence they appear to be moving. On the other hand the position of co-passengers is not changing with respect to us, hence they appear to be stationary.

 

Question 18

 

How are the motions of a wheel of a moving bicycle and a mark on the blade of a moving electric fan different? Explain.

Answer

 

The wheels of a moving bicycle depicts circular as well as rectilinear motion i.e., the wheels rotates and at the same time they cover a distance as well whereas the blade of a moving electric fan shows only circular motion.

 

Question 19

 

Three students measured the length of a corridor and reported their measurements. The values of their measurements were different. What could be the reason for difference in their measurements? (Mention any three)

 

Answer

 

Some of the reasons for difference in their measurement could be:

 

• Different measuring devices were used.
• The smallest length that could be measured by different devices maybe different.
• Measurement may not be along the shortest length in all three cases.
• The end of the corridor may not be easily accessible.
• The measuring devices may be faulty (not standardized)

 

Question 20

 

Boojho was riding in his bicycle along a straight road. He classified the motion of various parts of the bicycle as (i) rectilinear motion, (ii) circular motion and (iii) both rectilinear as well as circular motion. Can you list one part of the bicycle for each type of motion? Support your answer with reason.

 

Answer

 

(i) Handle Bar or Seat: The Handle bar or the seat doesn’t rotate with respect to the ground but 

  they only covers a distance(i.e., rectilinear motion).

 

(ii) Pedal: The Pedal is rotated by the bicycler and hence it shows circular motion.

 

(iii) Wheel: The wheel rotates as well as covers a distance. Hence it shows both rectilinear as well as circular motion.