9) Which statement about a ray is true?

Find the mass of the solid paraboloid Dequals={(r,thetaθ,z): 0less than or equals≤zless than or equals≤8181minus−r2, 0less th

Lubov Fominskaja [6]

Answer:

M = 5742π

Step-by-step explanation:

Given:-

- Find the mass of a solid with the density ( ρ ):

ρ ( r, θ , z ) = 1 + z / 81

- The solid is bounded by the planes:

0 ≤ z ≤ 81 - r^2

0 ≤ r ≤ 9

Find:-

Find the mass of the solid paraboloid

Solution:-

- The mass (M) of any solid body is given by the following triple integral formulation:

$M = \int \int \int {p ( r ,theta, z)} \, dV\\\\$

- We can write the above expression in cylindrical coordinates:

$M = \int\limits\int\limits_r\int\limits_z {r*p(r,theta,z)} \, dz.dr.dtheta \\\\M = \int\limits\int\limits_r\int\limits_z {r*[ 1 + \frac{z}{81}] } \, dz.dr.dtheta\\\\$

- Perform integration:

$M = \int\limits\int\limits_r{r*[ z + \frac{z^2}{162}] } \,|_0^8^1^-^r^2 dr.dtheta\\\\M = \int\limits\int\limits_r{r*[ 81-r^2 + \frac{(81-r^2)^2}{162}] } \, dr.dtheta\\\\M = \int\limits\int\limits_r{r*[ 81-r^2 + \frac{6561 -162r + r^2}{162}] } \, dr.dtheta\\\\M = \int\limits\int\limits_r{r*[ 81-r^2 + 40.5 -r +\frac{r^2}{162} ] } \, dr.dtheta\\\\M = \int\limits\int\limits_r{[ 121.5r-r^2 -\frac{161r^3}{162} ] } \, dr.dtheta\\\\$

$M = 2*\int\limits_0^\pi {[ 121.5r^2-r^3 -\frac{161r^4}{162} ] } |_0^6 \, dtheta\\\\M = 2*\int\limits_0^\pi {[ 121.5(6)^2-(6)^3 -\frac{161(6)^4}{162} ] } \, dtheta\\\\M = 2*\int\limits_0^\pi {[ 4375-216 -1288] } \, dtheta\\\\M = 2*\int\limits_0^\pi {[ 2871] } \, dtheta\\\\M = 5742\pi kg$

- The mass evaluated is M = 5742π

8 0

3 years ago

What is the percentage of 45/100?

kotykmax [81]

Percent=out of 100
45/100=45/

6 0

3 years ago

PLEASE HELP!! NO LINKS!!

dlinn [17]

Answer:

42.1 cm

Step-by-step explanation:

θ = 265°

Radius (r) = 9.1 cm

Arc length of major arc GH = θ/360 × 2πr

Plug in the values into the equation

Length of arc GH = 265/360 × 2 × π × 9.1

= 42.0886149

= 42.1 cm (nearest tenth)

6 0

3 years ago

A type of organism's cells split every minute. If the organism has 4 cells when the cells begin to split, how many cells will th

snow_lady [41]

Answer:

The total of cells will the organism have after 6 minutes is 252

Step-by-step explanation:

* Lets consider this problem as a geometric series

- There is a constant ratio between each two consecutive numbers

Ex:

# 5 , 10 , 20 , 40 , 80 , ………………………. (×2)

# 5000 , 1000 , 200 , 40 , …………………………(÷5)

* General term (nth term) of a Geometric series:

∵ U1 = a , U2 = ar , U3 = ar^2 , U4 = ar^3 , U5 = ar^4

∴ Un = ar^n-1

- Where r is the ratio between each two consecutive terms and

n is the position of the number in the series

* The sum of first n terms of a Geometric Progression is calculate from

Sn = a(1 - r^n)/1 - r

- In the problem the cell split every minute

- The organism has 4 cells when the cells begin to split

∴ a = 4

# 4 , 8 , 16 , 32 , .......

∴ r = 2

- The total of cells will the organism have after 6 minutes can

calculate from the rule of the sum

∴ S6 = 4(1 - 2^6)/1 - 2 = 4(1 - 64)/-1 = 4(-63)/-1 = 252 cells

4 0

4 years ago

Six different colored dice are rolled. Of interest is the number of dice that show a one. In words, define the random variable X

olga nikolaevna [1]

Answer:

Step-by-step explanation:

Six dice (each of a different color) are rolled. Since the number of times the 6 dice were rolled isn't stated, take it to be 1.

Hence, 6 dice are rolled at once for this experiment.

Of interest is the number of dice that show a "one". In other words, the variable in question (X) is:

The number of dots that show on the upward face of the rolled dice.

The values that X may take on are:

1 2 3 4 5 6

On average, how many dice would you expect to show a one?

One die.

How is this gotten? By finding the probability that a one or one dot appears when the 6 dice are rolled at once. Since there are 6 dice in number, and each die has the same 6 faces containing dots, the probability of getting a one is 1/6. In this case, one out of 6 dice is expected to show one dot.

Find the probability that all six dice show a dot in just one toss.

Logically, this probability is going to be very small! It is almost impossible for all 6 dice to land on the same face in just a single toss. In other words, expect many decimal places in the probability figure.

1/6 divided by 6 = 0.167/6 = 0.028 approximated to three decimal places.

This would also represent the probability that 2 dots, 3 dots, or any other number of dots appears on all dice in one toss!

Is it more likely (in this experiment) that 3 or 4 dice will show a one (a single dot)?

The answer is yes! It is more likely that 3 or 4 dice (instead of all 6) will show a one or will show the same number of dots.

Kudos!

7 0

3 years ago