Scale– complete the work in your copybook
1)When we have to create a technical drawing of an airplane, are we using scale increase or scale reduction (increasing or decreasing the airplane’s dimensions)? What is the scaleand what is the scale factor if we reduce all dimensions in 180 times?
Answers:
a)Scale reduction
b)Scale is 1 : 180
c)SF = 0.006 or 1/180
2)When drawing on paper, a part dimensions had to be
(a) increased in 15 times
(b) reduced in 80 times
.What is the scaleand what is the scale factorin each case above?
Answers
a)Scale is 15 : 1 and SF = 15
b)Scale is 1 : 80 and SF = 1/80 or 0.0125
3)The airplane is 35 m long. You want to draw it on paper, making it 25 cm long.
a)What is the scale?
b)What is the scale factor?
c)How wide will the wingspan be on paper, if it’s 16 m in reality?
Answers
a)Scale is 25 : 3500 or 1 : 140 (the last notation is the most appropriate)
b)SF = 25/3500 or 0.00714
c)11.4 cm
4)The bug is 4 mm long. You want to draw it on paper, making the picture 12 cm long
a)What is the scale?
b)What is the scale factor?
c)How long are its legs, if on the picture they are 2.5 cm?
Answers
a)12 : 4 or 3 : 1
b)3
c)0.83 cm or 8.3 mm
5)What would be the length of a pen if it measures 18 mm on the drawing, and the scale is 1:5?
Answer
90 mm or 9 cm
6)What would be the width of an object if it measures 30 mm on the drawing, and the scale is 6:1?
Answer
5 mm
7)What is the scale and the scale factor, if the real length of the object is 1 metre, and the length on the drawing is 5 cm?
Answers
a)Scale is 5 : 100 or 1 : 20 (the last notation is the most appropriate)
b)SF = 1/20 or 0.05
8)What is the scale and the scale factor, if the real length of the object is 7 mm, and the length on the drawing is 7 cm?
Answers
a)70 : 7 or 10 : 1
b)SF = 10
9)
a) Judging by the scale factors, identify whether the object is larger on paper or in real life:
1.1:100 / 4.1:12.1:5 / 5.25:1
3.50:1
Answers
a)
1. In real ,
2. In real,
3. On paper,
4. Same size,
5. On paper
b)For each example above, find the real length of a 20 mm line in a drawing made with that scale factor ratio
1. 2000 mm (200 cm or 2 m),
2. 100 mm (10 cm),
3. 0.4 mm
4. 20 mm (2 cm)
5. 0.8 mm
10)What is the scale and the scale factor in each example below?
a) A hair clip five times larger in the drawing than in reality
b) The plan for a new model of sports car with parts drawn 80 times smaller than in reality
c) A remote control drawn according to its actual dimensions
d) An electrical component enlarged 25 times in the drawing
e) The real length of an object is 1 meter, and the length on the drawing is 5 cm
Answers
a)Scale is 5 : 1, SF = 5
b)Scale is 1 : 80, SF = 1/80
c)Scale is 1 : 1, SF = 1
d)Scale is 25 : 1, SF = 25
e)Scale is 1 : 20, SF = 0.05
11)Draw on a scale of 1:15 a rectangle whose real length is 30 cm, and real height is 10 cm
Answer
The drawn rectangle will have length 2 cm, and height 0.67 cm on paper
12)A bird is 20 cm long. How long is it on paper? Answer for each of the scale factors below
a)SF = 1/50
b)SF = 9
c)SF = 0.3
d)SF = 20
Answers
a)0.4 cm
b)180 cm (1m 80 cm)
c)6 cm
d)400 cm (4 m)
13)For the following scale factors, 1 cm on paper will represent how many cm in real life?
a)SF = 0.08
b)SF = 10
c)SF = 3.5
d)SF = 1
e)SF = 0.15
Answers
a)12.5 cm
b)0.1 cm
c)0.29 cm
d)1 cm
e)6.7 cm