All categories

3 years ago

A change of color is a sign that a chemical reaction is taking place. true or false

Physics

1 answer:

Citrus2011 [14]3 years ago

3 0

That is true. Change in color, formation of a precipitate, and production of gas are the three chemical changes.

You might be interested in

Help awnser need experts

pishuonlain [190]

12. The answer would be C. 1.50 s. This is because if you divide 60 by 40, you will get 1.5.

13. For this one I'm not sure, but what I can tell you is that the heavier something is the faster it will sink, the lighter it is, it will float.

5 0

4 years ago

A refrigerator is being pulled up a ramp with a horizontal force P, which acts at the top corner. The refrigerator has a mass of

vaieri [72.5K]

Answer:

(a) P = 459.055 N.

(b) the refrigerator tips.

Explanation:

Given, the angle of ramp is 20°.

When the weight of refrigerator is resolved in directions parallel and perpendicular to ramp, 75×g×sin(20°) and 75×g×cos(20°).

⇒ normal contact force is 75×g×cos(20°).

⇒ frictional force is 0.3×75×g×cos(20°) = 207.414 N

so, total opposite force is 207.414 + 75×g×sin(20°) = 459.055 N.

so, the force needed is P = 459.055 N

And as the moment due to both opposite force and P force are in same direction the refrigerator tips rather than just sliding.

4 0

3 years ago

Say I have a series circuit with 20v and four 65 ohm resistors, what is the current in each resistor?

Komok [63]

Data:

$E = 20 V$
$R_{1} = 65\Omega$
$R_{2} = 65\Omega$
$R_{3} = 65\Omega$
$R_{4} = 65\Omega$

Now that we have all the values we need properly identified, simply calculate the equivalent total resistance of the circuit and the intensity of the total electric current using the Ohm's Law:

 $R_{T} = R_{1} + R_{2} + R_{3} + R_{4}$
$R_{T} = 65 + 65 + 65+ 65$
$R_{T} = 260\Omega$

Like this:

$I_{T} = \frac{E}{ R_{T} }$

$I_{T} = \frac{20}{ 260 }$
$I_{T} = 0,076923076...$

$\boxed{\boxed{I_{T} \approx 0,07A}}$
Answer:
The intensity of the total electric current
 $\boxed{\boxed{I_{T} \approx 0,07A}}$

P.S:. Since the association is in series, the current of 0.07A is the same for all resistors.

4 0

3 years ago

A student puts a beaker of boiling water where it touches a block of ice. Which two statements are true? A. Thermal energy will

rodikova [14]

Answer: C and D

Explanation: I’m pretty sure it’s C and D I got the same question but cold water let me know please, thanks!

6 0

4 years ago

Read 2 more answers

It is warmer near the equator because that is where the Earth gets the most direct sunlight. T or f

Anni [7]

True this is true bc yes as you said you're at the most direct point of sunlight