Answer:
Part A: 2,100 cm²
Part B: 5,880 cm³
Step-by-step explanation:
Area 1st rectangle = 15*28
Area 2nd rectangle = 20*28
Area 3d rectangle = 12*28
Area 4th rectangle = 13*28
Area trapezoid =(1/2) ( base1 + base2)*height = (1/2) (15+20)*12
There are two such trapezoids.
Complete surface area = 15*28 + 20*28 +12*28+13*28 + 2 *(1/2)(15+20)*12 =
= 2,100 cm²
Part B.
Volume = base area*height prism
Base area = area trapezoid = (1/2) (base1 a+ base2)*heght trapezoid =
= (1/2)*(20+15)*12
Volume = (1/2)*(20+15)*12*28 = 5,880
Answer:
14.99 hours
Step-by-step explanation:
The formula for half-life is given as,
R/R' = 2ᵃ/ᵇ...................... Equation 1
Where R= Original mass of sodium-24, R' = mass of Sodium-24 after disintegration, a = Total time taken for sodium-24 to disintegrate, b = half-life of sodiun-24.
Given: R = 1 kg, R' = 0.0156 kg, a = 90 hours
Substitute into equation 1 and solve for b
1/(0.0156) = 2⁹⁰/ᵇ
Taking the log of both side
log[1/(0.0156)] = log(2⁹⁰/ᵇ)
log[1/(0.0156)] = 90/b(log2)
90/b = log[1/(0.0156)]/log2
90/b = 6.0023
b = 90/6.0023
b = 14.99 hours
b = 14.99 hours.
Hence the half-life of Sodium-24 is 14.99 hours
4+4=8
1/2+1/2=1
8+1=9
4+4=8
1/2+1/2=1
8+1=9
9+9=18
4+18=22+1/2=22 1/2
Answer:
-9.Try to caculate it, My friend
Answer:
I believe the answer is 7.5 degrees
Step-by-step explanation:
7.5 + 82.5 equals 90°
complementary angles add up to 90 degrees