The answer for this question would be choice "<span>B. The average annual dose of background radiation is 250 times smaller than the dose linked to increased cancer risk."
You only have to compare 4.0 x 10^-4 and 1.0 x 10^-1. And if you can observe carefully, when you try to multiply the average annual dose of background radiation by 250, you would get 0.1 which is equivalent to the amount of annual dose linked to increased cancer risk. Therefore, the answer is B.</span>
Answer:
a) τmax = 586.78 P.S.I.
b) σmax = 15942.23 P.S.I
Explanation:
D = 3.81 in
d = 3.24 in
P = 930 lb
L = 3.7 ft = 44.4 in
a) The maximum horizontal shear stress can be obtained as follows
τ = V*Q / (t*I)
where
V = P = 930 lb
Q = (2/3)*(R³- r³) = (1/12)*(D³- d³) = (1/12)*((3.81 in)³- (3.24 in)³)
⇒ Q = 1.7745 in³
t = D - d = 3.81 in - 3.24 in = 0.57 in
I = (π/64)*(D⁴-d⁴) = (π/64)*((3.81 in)⁴- (3.24 in)⁴) = 4.9341 in⁴
then
τ = (930 lb)*(1.7745 in³) / (0.57 in*4.9341 in⁴)
⇒ τmax = 586.78 P.S.I.
b) We can apply the following equation in order to get the maximum tension bending stress in the pipe
σmax = Mmax *y / I
where
Mmax = P*L = 930 lb*44.4 in = 41292 lb-in
y = D/2 = 3.81 in /2 = 1.905 in
I = 4.9341 in⁴
then
σmax = (41292 lb-in)*(1.905 in) / (4.9341 in⁴) = 15942.23 P.S.I
Answer
Given,
Average speed of Malcolm and Ravi = 260 km/h
Let speed of the Malcolm be X and speed of the Ravi Y.
From the given statement
....(i)
....(ii)
Adding both the equations
3 X = 600
X = 200 km/h
Putting value in equation (i)
Y = 520 - 200
Y = 320 Km/h
Speed of Malcolm = 200 Km/h
Speed of Ravi = 320 Km/h
