school starts at 7:00 a.m. and gets over at 12:30 p.m. if to break time is from 9:50 a.m. to 10:10 a.m. what is the ratio of the break time the total time the students spend at school
Answers
Answer:
Given:-
A metal pipe is 77 cm long. (length of pipe = 77 cm)
The inner diameter of the pipe is 4 cm (d1 = 4 cm)
The outer diameter of the pipe is 4.4 cm (d2 = 4.4 cm)
Find:-
CSA (curved surface area)
TSA (total surface area)
Solution:-
The inner diameter of the pipe is 4 cm.
So, the inner radius of pipe = 2 cm (half of the diameter)
The outer diameter of the pipe is 4.4 cm
So, the outer radius of pipe = 2.2 cm
\sf{CSA\:of\:cylinder\:=\:2\pi\:rh}CSAofcylinder=2πrh
For outer radius
→ 2 × 22/7 × 2 × 77
→ 4 × 22 × 11
→ 968 cm²
For inner radius
→ 2 × 22/7 × 2.2 × 77
→ 4.4 × 22 × 11
→ 1064.8 cm²
Now,
\sf{TSA\:of\:cylinder\:=\:Outer\:CSA\:+\:Inner\:CSA\:-\:thickness}TSAofcylinder=OuterCSA+InnerCSA−thickness
→ 968 + 1064.8 - thickness ...(1)
Thickness = 2π (r2² - r1²)
→ 2 × 22/7 [(2.2)² - (2)²]
→ 44/7 (4.84 - 4)
→ 44/7 (0.84)
→ 5.28
Substitute value of thickness in (1)
→ 2032.8 + 5.28
→ 2038.08 cm²
•°• CSA for inner radius is 968 cm² and for outer radius is 1064.8 cm²
TSA of metal pipe is 2038.08 cm²
Answer:
2:33 hope it helps you