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3 years ago

After a match has burned which of these is not proof that a chemical reaction occurred?

2 answers:

4 0

In my estimation I would say C, I was leaning towards A, but I believe that would merely be "incomplete combustion." I hope this was semi-helpful!

Elden [556K]3 years ago

4 0

C. i say this because heat and smoke are signs that a chemical reaction is happening. for d if its gone obviously something had to have happened whether it was a chemical or physical reaction so whats left is C.

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While driving down his street one evening, Jonah notices that his neighbor has laid out an electric fan for the garbage to pick

Kryger [21]

Answer: I have no idea either i need help aswell

Explanation:

4 0

3 years ago

Read 2 more answers

Force F=2.0N i - 3.0N k acts on a pebble with position vectorr=0.50m j - 2.0m k relative to the origin. In unit vector notation,

klasskru [66]

Answer with Explanation:

We are given that

Force acts on a pebble= $2\hat{i}-3\hat{k}$ N

Position vector= $r=0.5\hat{j}-2\hat{k}$ m

a.We have to find the resulting torque on the pebble about origin.

Torque= $r\times F$

Substitute the values then we get

$Torque= (0.5j-2k)\times (2i-3k)$

Torque= $-k-1.5i-4j$ N-m

By using $i\times j=k,j\times k=i,k\times i=j,j\times i=-k,k\times j=-i,i\times k=-j,i\times i=j\times j=k\times k=0$

b. $r=2i-3k$

$r-r_1=(0.5j-2k)-(2i-3k)=-2i+0.5j+k$

Torque about point (2,0,-3)

$\tau=(-2i+0.5j+k)\times (2i-3k)$

$\tau=-6j-k-1.5i+2j=-1.5i-4j-k$ N-m

6 0

3 years ago

Placed exactly between two oppositely charged point charges, a test charge (the

Sveta_85 [38]

Zero maximum force (N) or field strength (N/C). ... minimum /maximum field strength.

6 0

3 years ago

object is placed 15cm in front of a plane mirror. If the mirror is moved further 5cm away from the object and the image is

solong [7]

Answer:

The image will most likely be 20cm in front the mirror since the mirror was placed further 5cm.

4 0

3 years ago

Read 2 more answers

If racing alcohol has a mass density of 790kg/m3, what mass will a 1250-litre tank hold?

Marina86 [1]

Density = Mass per unit Volume
that is,
D = m / V

Now,
We've been provided with,

Density = 790 kg/m³
Volume = 1250 litres = 1.250 m³

Now,
$density = \frac{mass}{volume} \\ 790 = \frac{m}{1.250} \\ 790 \times 1.250 = m \\ m = 790 \times 1.250 \\ m = 790 \times \frac{1250}{1000} \\ m = 790 \times \frac{5}{4} \\ m = 197.5 \times 5 \\ m = \frac{1975}{10} \times 5 \\ m = \frac{1975}{2} = 987.5 \: kg$

987.5 kg of mass will a 1250 litres tank will hold.

Please Mark It As Brainliest Answer_

3 0

3 years ago