Answer:
The mass of the pipe is 
Step-by-step explanation:
step 1
Find the volume of the steel pipe
The volume is equal to the area of outside circle minus the area of inside circle, multiplied by the length of the pipe
so
![V=\pi [r2^{2}-r1^{2}]L](https://tex.z-dn.net/?f=V%3D%5Cpi%20%5Br2%5E%7B2%7D-r1%5E%7B2%7D%5DL)
we have
---> the radius is half the diameter
---> the radius is half the diameter


substitute
=59.66\ cm^{3}](https://tex.z-dn.net/?f=V%3D%283.14%29%5B1%5E%7B2%7D-0.9%5E%7B2%7D%5D%28100%29%3D59.66%5C%20cm%5E%7B3%7D)
step 2
Find the mass
The mass is equal to the density multiplied by the volume
so

Answer: The distance between them is 230.65 miles.
Step-by-step explanation:
Since we have given that
Speed of plane A (b) = 200 miles per hour
Speed of plane B (c) = 300 miles per hour
Angle between them = 50°
So,
We will use the "Cosine formula", we get

So, distance between the two planes after one hour will be

So, the distance between them is 230.65 miles.
Answer: 1.5 meters
Step-by-step explanation:
Given: A lake near the Arctic Circle is covered by a sheet of ice during the cold winter months. S
S(t) models the ice sheet's thickness (in meters) as a function of time t (in weeks) 
if we put x=0, then

So 4 meters is the initial thickness
To find the thickness after 6 weeks, put x=6 we get

Decrease in thickness every 6 weeks= 
Answer:
Step-by-step explanation:
I'd tell her that if (and only if) her prediction is correct, the probability of getting tails is 0.5. Actually, the probability of getting heads would be the same, 0.5.
In real life she would not necessarily get 240 tails out of 480 tosses, but the mean value of the number of tails would indeed be close to 0.5.
Answer:
2.5477 feet
Step-by-step explanation:
Refer the image attached to understand my solution.
BC = height of lamppost.
DE = Julia
AD = shadow of Julia
BD = 2 feet. AD = 5 feet
BA = BD + AD
= 2 + 5 = 7 feet
In ΔABC
tan 20° = 
BC = 7 * tan 20°
BC = 2.5477 feet
SO the height of lamppost = 2.5477 feet