maths ''

i don't understand that the 3 questions ..
plz help me /3\


1. The diameter of a wheel is 0.5 m. How far does it travel in 10 revolutions? { Take π' = 3.14 }

2. A coin rolling along a straight line covers 110 cm in 14 revolutions. Find the diameter of the coin { Take π' = 22/7 }

3. The difference between the radii of two circles is 3 cm. Find the difference in their circumferences. { Express your answer in terms of π }

[[i] 本帖最後由 kate;) 於 2006-12-5 07:44 PM 編輯 [/i]]

咩叫PI=口=?

[quote]原帖由 [i]L-HERMIA`[/i] 於 5/12/2006 19:38 發表
咩叫PI=口=? [/quote]
姐 係 3.14 同 22/7 -u-''
我 打 唔 到 呀 ><

[quote]原帖由 [i]L-HERMIA`[/i] 於 2006-12-5 07:38 PM 發表
咩叫PI=口=? [/quote]
PI姐係 π

[quote]原帖由 [i]cat.[/i] 於 5/12/2006 19:43 發表

PI姐係 π [/quote]
就 係 拉 *3*
thx cat >V<

直徑 X PIE = 圓周
1) 0.5 x pie x 10 = 15.70796327

2)110/14/ (22/7) = 2.5   (唔知你取幾多sig figure)
第3題諗下先 -  -"

[[i] 本帖最後由 {ｃhiｎ} 於 2006-12-5 08:15 PM 編輯 [/i]]

1. The diameter of a wheel is 0.5 m. How far does it travel in 10 revolutions? { Take π' = 3.14 }
    0.5 × 3.14 × 10
   ﹦1.570796327 × 10
   ﹦15.70796327

2. A coin rolling along a straight line covers 110 cm in 14 revolutions. Find the diameter of the coin { Take π' = 22/7 }
   110 ÷ 14 ÷ 22/7
  ﹦55/7 × 7/22
  ﹦5/2

↓超級唔肯定呢***

3. The difference between the radii of two circles is 3 cm. Find the difference in their circumferences. { Express your answer in terms of π }
   
  Let y be the smaller radius, y+3 be the larger radius.
   [ ( y ﹢3 ) × 2 × π ] ﹣ ( y × 2 ×  π )
  ﹦( 2y ﹢ 6 × π ) - 2πy
  ﹦2πy ﹢ 6π  - 2πy
  ﹦6π

希望幫到你啦*

[quote]原帖由 [i]{ｃhiｎ}[/i] 於 5/12/2006 19:54 發表
直徑 X PIE = 圓周
1) 0.5 x pie x 10 = 15.70796327

2)110/14/ (22/7) = 2.5   (唔知你取幾多sig figure)
第3題諗下先 -  -" [/quote]
第 2 題 係 唔 係 姐 係 .. 14 分 之 110 ÷7 分 之 22 ?

[quote]原帖由 [i]kate;)[/i] 於 2006-12-5 07:36 PM 發表
i don't understand that the 3 questions ..
plz help me /3\


1. The diameter of a wheel is 0.5 m. How far does it travel in 10 revolutions? { Take π' = 3.14 }
10 x (0.5 π' ) = 15.6

2. A coin rolling along a straight line covers 110 cm in 14 revolutions. Find the diameter of the coin { Take π' = 22/7 }
where D be the diameter
110 = 14 x (22D/7)
D = 5/2

3. The difference between the radii of two circles is 3 cm. Find the difference in their circumferences. { Express your answer in terms of π }
2x 3 x π = 6π
[/quote]