Monday 28 December 2020

Chapter 10 Motion And Measurement of Distances

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Chapter 10 Motion and MeasureMent of distances

 

ACTIVITY- 3 : To measure the length of a curved line.

 

Question 1- The length of a curved line can be measured by a metre scale directly. (True/False)

Answer- False.

 

Question 2- The metre is standard unit of length. (True/False)

Answer- True.

 

EXERCISE

 

 

Question 1- Fill In The Blanks.

 

a. One metre is 100 cm.

b. Five kilometer is 5000 m.

c. Motion of a child on a swing is periodic motion.

d. Motion of the needle of a sewing machine is periodic motion.

e. Motion of wheel of a bicycle is circular motion.

 

Question 2- Write True Or False.

a. Hand span or feet step are standard units of measurement. (False)

b. Standard unit of length is metre. (True)

c. Motion of train on railway track is an example of linear motion. (True)

d. Length of a curved line can be measured by a scale. (False)

e. Motion of hands of a clock is a circular motion. (True)

 

Question 3- Match The Column ‘A’ With Column ‘B’.

A                              B

 

a. Metre                   a. Periodic motion (e)

b. Circular motion   b. Length (a)

c. 1 km                     c. Linear motion (d)

d. Train on track      d. Hands of clock (b)

e. Swing                   e. 1000m (c)

 

 

Question 4. Choose The Correct Answer.

 

(i). In motor vehicles which of the following is used for measuring the distance covered by the vehicle?

a) Speedometer b) Odometer () c) Thermometer d) None of these

 

(ii). A student want to take the measurements of a brick, for this purpose which unit he should use?

a) kilometre

b) metre

c) centimeter ()

 d) Hand span

 

(iii). The motion of wings of a moving fan is …………..

a) Circular motion ()

b) Linear motion

c) Both (a) and (b)

d) None of these

 

(iv). Which of among is false?

a) 1000m = 1 km

b) 100 mm = 1cm ()

c) 100cm = 1m

d) 10mm = 1cm

 

Question 5- Very Short Answer Type Questions.

 

(i) Name some means of transport used in ancient time?

Answer- Animals like horses, carts, boats etc.

 

(ii) Give two examples of periodic motion.

Answer- Motion of swing, motion of needles of clock.

 

Question 6- Short Answer Type Questions.

 

(i) Give two examples of transport used on land, water and air.

Answer- Land- Car, train, bicycle.

        Water- Boat, ship, submarine.

        Air- Airplane, helicopter, rocket.

 

(ii) What is distance?

Answer- Distance is the length of space between two points.

 

(iii) Arrange the following lengths in their increasing magnitude:

     1 metre, 1 centimetre, 1 kilometre, 1 millimetre.

Answer- 1 millimetre < 1 centimetre < 1 metre < 1 kilometre.

 

(iv)  Write the similarities and differences between the motion of a bicycle and a ceiling fan that has been switched ON.

Answer- Similarity: Both the ceiling fan and the wheels of a bicycle show circular motion.

Difference: A bicycle shows linear motion while a ceiling fan does not.

 

(v) The distance between Radha’s home and her school is 3250 m. Express this distance into km.

Answer- 3250 m = 3250/1000 = 3.25 km.

 

Question 7- Long Answer Type Questio

 

(i) Describe what precautions should be taken while measuring length or breadth of an object?

Answer- (1) We should use appropriate unit of length.

(2) One end of length should be parallel to zero of scale.

(3) While taking reading position of eye should be correct.

 

(ii) How many types of motion are there? Give examples for each type.

Answer- Motion is generally of three types –

(1) Linear Motion- Train of straight railway track, car on straight road.

(2) Circular Motion- Motion of wings of fan, Motion of hands of clock.

(3) Periodic Motion- Motion of swing, motion of needles of clock.

 

(iii) Write an activity for measuring the length of a curved line?

Answer- Make a curved line AB on a chart. Make a knot on one end (A) on a thread and place the knot on one end of curved line. Now place thread on curved line by stretching in small portions up to the other end (B) of curved line. Make another knot on the thread where it touches the point B. Now stretch the thread along a meter scale and measure distance between two knots. This is the length of given curved line.

 

(iv) Why hand span or footsteps cannot be used as standard units of measurement?

Answer- Because length of hand span and footsteps vary from person to person. So length measured by hand span or footsteps cannot be same for different people. Hence we cannot use hand span or footsteps as standard unit.