Answer:
He would need 58 yards of material.
Step-by-step explanation:
If there are 4 sets of pillows and comfoters, that means there are 8 pillows and 4 comfoters.
If each pillow uses 0.75 yards of material, 8x0.75= 6
If each comfoters uses 13 yards of material, 4x13= 52
6+52= 58 yards of material.
The magnification is 0.54
Given,
The distance between object and concave lens, u = -21 cm
Focal length of the concave lens, f = -25 cm
Let m be the magnification.
m = v/u
Here v is the position of image.
We have to find v first.
By using lens equation we can determine v.
That is,
1/f = 1/v – 1/u
So,
- (1/25) = 1/v – (-1/21)
- (1/25) = 1/v + 1/21
1/v = - (1/25) – 1/21
1/v = (-25 – 21) / (21 x 25)
1/v = - (46/525)
Therefore v = - (525/46)
v = -11.41 cm
Now we have to find magnification, m.
m = v/u
= (-11.41) / (-21)
= 0.54
Here magnification is 0.54
Learn more about concave lens here: brainly.com/question/12944945
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Answer:
12
Step-by-step explanation:
