All categories

3 years ago

Which of the following is not a common property of basesp

Physics

1 answer:

Hatshy [7]3 years ago

6 0

Explanation:

Bases taste bitter, feel slippery, and conduct electricity when dissolved in water. Indicator compounds such as litmus can be used to detect bases. Bases turn red litmus paper blue. The strength of bases is measured on the pH scale.

You might be interested in

A car travels from rest to 85 m/s and covers 150 meters. How LONG did<br> that take? *

kherson [118]

Answer:

51.76

Explanation:

4 0

2 years ago

Newton's Law of Cooling states that the rate of cooling of an object is proportional to the temperature difference between the o

julsineya [31]

Answer:

1) $k=-\frac{1}{46}\approx -0.02$

2) $\textit{Limiting value} = 24$

3) $T(10)\approx \frac{494611944}{6436343}\approx 76.8$

Explanation:

First of all note that

$T_s=24$ is the surroundings temperature, the temperature of the room where the cup of coffee is. Then, the differential equation is:

$\frac{dT}{dt}=k(T-24)$

Also, note that all units are in degrees celsius and minutes. Then, we don't have to convert units. Let's not write units explicitly from now on.

Explanation

1) We have that

$\textit{rate of cooling}=\frac{dT}{dt}=1,\quad T=70$

at some point - the exact time at which this is true doesn't really play any role because the equation doesn't have t on the right hand side. Then, from the equation we get

$1=-(70-24)=46k\Rightarrow k=-\frac{1}{46}\approx -0.02$

The minus comes from considering the temperature must decrease. With this value we can write the equation more explicitely:

$\frac{dT}{dt}=-\frac{1}{46}(T-24)$

2) The coffee is cooling off as time goes by, and it won't get any cooler than 24 degrees celsius because that's the temperature of the room. Then, in the long run, the temperature of the coffee is 24 degrees celsius.

3) Remember that Euler's method consists of using an initial exact measurement to predict what will happen in the future, approximately. There is a formula to make those predictions an it depends on the time step they gave us. Let's compute things first and then I tell you the equations we used.

In this case we know that we start with a 90 degrees celsius cup of coffee, or, in terms of math,

$T(0)=90$

Then, we can predict:

$T(2)\approx 90+2\left[-\frac{1}{46}(90-24)\right]=\frac{2004}{23}\approx 87.1$

Let's use fractions so we don't lose accuracy from now. With this number we can make an approximation of the temperature after 2 more seconds:

$T(4)\approx \frac{2004}{23}+2\left[-\frac{1}{46}\left(\frac{2004}{23}-24\right)\right]=\frac{44640}{529}\approx 84.4$

and then

$T(6)\approx \frac{44640}{529}+2\left[-\frac{1}{46}\left(\frac{44640}{529}-24\right)\right]=\frac{994776}{12167}\approx 81.8$

and then

$T(8)\approx \frac{994776}{12167}+2\left[-\frac{1}{46}\left(\frac{994776}{12167}-24\right)\right]=\frac{22177080}{279841}\approx 79.2$

and finally, the number we wanted to find:

$T(10)\approx \frac{22177080}{279841}+2\left[-\frac{1}{46}\left(\frac{22177080}{279841}-24\right)\right]=\frac{494611944}{6436343}\approx 76.8$

I hope you noticed the pattern to compute the next prediction:

$\textit{next prediction} = \textit{previous one (or exact value if it's the first step)}\\+ h\ast(\textit{right hand side of the differential equation at the previous one})$

5 0

3 years ago

Can someone pls do this for me for 20 pts

Ann [662]

You need to delete this question ASAP! You put out your first and last name.

6 0

3 years ago

Read 2 more answers

Remember to identify all your data, write the equation, and show your work.

Paraphin [41]

Answer:

I believe it's 8.09 seconds, but I'm rusty on my physics.

Explanation:

The equation for solving the time it takes for an object to fall is $\sqrt{2d/g}$

So multiply the distance times 2, and you get 642 meters. Then you divide by gravities acceleration constant, 9.8, and you get 65.51. Finally, $\sqrt{65.51}$ , and you get 8.09 seconds.