Class 6 Mathematics Chapter 5 |
Understanding Elementary Shapes | Exercise 5.2
1. What fraction of a clockwise revolution does the hour hand of a clock turn through, when it goes from
(a) 3 to 9
(b) 4 to 7
(c) 7 to 10
(d) 12 to 9
(e) 1 to 10
(f) 6 to 3
Answer:
a) When the hour hand goes from 3 to 9 , it will rotate by 2 right angles.
b) When the hour hand goes from 4 to 7 , it will rotate by 1 right angles.
c) When the hour hand goes from 7 to 10 , it will rotate by 1 right angles.
d) When the hour hand goes from 12 to 9 , it will rotate by 3 right angles.
e) When the hour hand goes from 1 to 10 , it will rotate by 3 right angles.
f) When the hour hand goes from 6 to 3 , it will rotate by 3 right angles.
Question 2. Where will the hand of a clock stop if it
(a) starts at 12 and makes 1/2 of a revolution, clockwise?
(b) starts at 2 and makes 1/2 of a revolution, clockwise?
(c) starts at 5 and makes 1/4 of a revolution, clockwise?
(d) starts at 5 and makes 3/4 of a revolution, clockwise?
Answer:
(a) At 6
(b) At 8
(c) At 8
(d) At 2
3. Which direction will you face if you start facing
(a) east and make 1/2 of a revolution clockwise?
(b) east and make 1 and 1/2 of a revolution clockwise?
(c) west and make 3 /4 of a revolution anti-clockwise?
(d) south and make one full revolution? (Should we specify clockwise or anti-clockwise for this last question? Why not?)
Answer:
(a) West
(b) West
(c) North
(d) South
4. What part of a revolution have you turned through if you stand facing
(a) east and turn clockwise to face north?
(b) south and turn clockwise to face east?
(c) west and turn clockwise to face east?
Answer:
(a) 3/4
(b) 3/4
(c) 1/2
5. Find the number of right angles turned through by the hour hand of a clock when it goes from
(a) 3 to 6
(b) 2 to 8
(c) 5 to 11
(d) 10 to 1
(e) 12 to 9
(f) 12 to 6
Answer 5:
(a) One right angle
(b) Two right angles
(c) Two right angles
(d) One right angle
(e) Three right angles
(f) Two right angles
6. How many right angles do you make if you start facing
(a) south and turn clockwise to west?
(b) north and turn anti-clockwise to east?
(c) west and turn to west?
(d) south and turn to north?
Answer:
(a) One right angle
(b) Three right angles
(c) Four right angles
(d) Two right angles
7. Where will the hour hand of a clock stop if it starts
(a) from 6 and turns through 1 right angle?
(b) from 8 and turns through 2 right angles?
(c) from 10 and turns through 3 right angles?
(d) from 7 and turns through 2 straight angles?
Answer:
(a) At 9
(b) At 2
(c) At 7
(d) At 7