Electrical energy is sold by the kilowatt hour How much would it cost to heat a hot tub from 15 to 43

Levart [38]

Answer: i think it is for 16, Infectious diseases commonly spread through the direct transfer of bacteria. for 17 i think In biology, immunity is the capability of multicellular organisms to resist harmful microorganisms. i dont have a clue about the others but i hope this is right or atleast helps

Explanation:

5 0

3 years ago

wide tube that extends down from the bag of solution, which hangs from a pole so that the fluid level is 90.0 cm above the needl

Bingel [31]

Answer:

The average gauge pressure inside the vein is 110270.58 Pa

Explanation:

This question can be solved using the Bernoulli's Equation. First, in order to determine the outlet pressure of the needle, we need to find the total pressure exerted by the atmosphere and the fluid.

$P_f: fluid's\ pressure\\P_f= \rho g h=1025\frac{kg}{m^3} \times 9.8 \frac{m}{s^2} \times 0.9 m=9040.5 Pa \\P_T: total\ pressure\\P_T=P_{atm}+P_f\\P_T=101325 Pa + 9040.5 Pa=110275.5 Pa\\$

Then, we have to find the fluid's outlet velocity with the transversal area of the needle, as follows:

$S: transversal\ area \\S= \pi r^2=\pi (0.200 \times 10^{-3})^2=5.65 \times 10^{-7} m^2\\v=\frac{F}{S}=\frac{5.55 \times 10^{-8} \frac{m^3}{s}}{5.65 \times 10^{-7} m^2}=0.98\times 10^{-1} \frac{m}{s}$

As we have all the information, we can complete the Bernoulli's expression and solve to find the outlet pressure as follows:

$P_T-P_{out}=\frac{1}{2} \rho v^2\\P_{out}=P_T-\frac{1}{2} \rho v^2=110275.5 Pa-\frac{1}{2} 1025\frac{kg}{m^3} (0.98\times 10^{-1} \frac{m}{s})^2=110275.5 Pa-4.92 Pa =110270.58 Pa$

6 0

3 years ago

A manufacturer of CD-ROM drives claims that the player can spin the disc as frequently as 1200 revolutions per minute.

Leya [2.2K]

a. 7.0 m/s

First of all, we need to convert the angular speed (1200 rpm) from rpm to rad/s:

$\omega = 1200 \frac{rev}{min} \cdot \frac{2\pi rad/rev}{60 s/min}=125.6 rad/s$

Now we know that the row is located 5.6 cm from the centre of the disc:

r = 5.6 cm = 0.056 m

So we can find the tangential speed of the row as the product between the angular speed and the distance of the row from the centre of the circle:

$v=\omega r = (125.6 rad/s)(0.056 m)=7.0 m/s$

b. $875 m/s^2$

The acceleration of the row of data (centripetal acceleration) is given by

$a=\frac{v^2}{r}$

where we have

v = 7.0 m/s is the tangential speed

r = 0.056 m is the distance of the row from the centre of the trajectory

Substituting numbers into the formula, we find

$a=\frac{(7.0 m/s)^2}{0.056 m}=875 m/s^2$

3 0

3 years ago

A lunar module weighs 12 metric tons on the surface of the Earth. How much work is done in propelling the module from the surfac

zhuklara [117]

Answer:

W=76.55 miles.metric tons

Explanation:

Given that

Weight on the earth = 12 tons

So weight on the moon =12/6 = 2 tons

( because at moon g will become g/6)

As we know that

$F=\dfrac{K}{x^2}$

Here x= 1100 miles

F 2 tons

$2=\dfrac{K}{1100^2}$

So

$K=2.4\times 10^6$

We know that

Work = F. dx

$W=\int_{x_1}^{x_2}F.dx$

$W=\int_{1100}^{1140}\dfrac{2.4\times 10^6}{x^2}.dx$

$W=-2.4\times 10^6\left[\dfrac{1}{x}\right]_{1100}^{1140}$

$W=-2.4\times 10^6\left[\dfrac{1}{1140}-\dfrac{1}{1100}\right]$

W=76.55 miles.metric tons

6 0

3 years ago

Which means for obtaining hydrogen from water would require the most energy??

Flauer [41]

I think the correct answer would be to electrolyze water (run an electric current through it) to decompose it into hydrogen and oxygen. Assuming 100% efficiency, it is said that it needs about 40kWh per kilogram of water to fully decompose it.

8 0

3 years ago