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3 years ago

5

Which changes do not involve forming or breaking chemical bonds? rusting and cutting burning and melting burning and digesting b

oiling and melting

1 answer:

r-ruslan [8.4K]3 years ago

6 0

Answer:

boiling and melting!

Explanation:

These do not make any changes chemically to the substance.

Hope this helps!

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A student produces a power of p = 0.87 kw while pushing a block of mass m = 75 kg on an inclined surface making an angle of Î¸ =

Paul [167]

When block is pushed upwards along the inclined plane

the net force applied on the block will be given as

$F_{net} = mg sin\theta + \mu_k mg cos\theta$

here we know that

m = 75 kg

$\theta = 8.5 degree$

$\mu_k = 0.16$

now plug in all values into this

$F_{net} = 75\times 9.8 sin8.5 + 0.16 \times 75\times 9.8 cos8.5$

$F = 225 N$

now for finding the power is given as

$P = Fv$

$0.87 \times 10^3 = 225 \time v$

$v = \frac{870}{225} = 3.87 m/s$

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2 years ago

The starships of the Solar Federation are marked with the symbol of the Federation, a circle, whereas starships of the Denebian

Llana [10]

Complete question

The complete question is shown on the first uploaded image

Answer:

The velocity is $v = c* \sqrt{1 - \frac{1}{n^2} }$

Explanation:

From the question we are told that

a = nb

The length of the minor axis of the symbol of the Federation, a circle, seen by the observer at velocity v must be equal to the minor axis(b) of the Empire's symbol, (an ellipse)

Now this length seen by the observer can be mathematically represented as

$h = t \sqrt{1 - \frac{v^2}{c^2} }$

Here t is the actual length of the major axis of of the Empire's symbol, (an ellipse)

So t = a = nb

and b is the length of the minor axis of the symbol of the Federation, (a circle) when seen by an observer at velocity v which from the question must be the length of the minor axis of the of the Empire's symbol, (an ellipse)

i.e h = b

So

$b = nb [\sqrt{1 - \frac{v^2}{c^2} } ]$

$[\frac{1}{n} ]^2 = 1 - \frac{v^2}{c^2}$

$v^2 =c^2 [1- \frac{1}{n^2} ]$

$v^2 =c^2 [\frac{n^2 -1}{n^2} ]$

$v = c* \sqrt{1 - \frac{1}{n^2} }$

6 0

3 years ago

A submarine emerges 1/9 of its volume when it partially floats on the sea surface. For make it completely submerge it is necessa

AleksAgata [21]

Answer:

4,524,660 N

Explanation:

Assuming the submarine's density is uniform, 1/9th of the submarine's mass is equal to the mass of the displaced water.

m/9 = (1026 kg/m³) (50 m³)

m = 461,700 kg

mg = 4,524,660 N

3 0

2 years ago

Objective lenses are contained in a ____________ that can be turned to put a particular objective lens in place to be used.

Masteriza [31]

Answer:

Revolving nosepiece

Explanation:

The revolving nosepiece is one of the parts of a microscope, used for holding the objective lenses. They can be turned to put a particular objective lens in place to be used in order to vary magnification.

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3 years ago

d. The force is doubled and the object’s mass is halved? 18. ||| A man pulling an empty wagon causes it to accelerate at 1.4 m/s

Harrizon [31]

Answer:

$a' = 0.35 m/s^2$

Explanation:

Let say the empty wagon has mass "M"

now by newton's II Law we will have

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now we will have

$F = 1.4 M$

now a child of mass three times the mass of wagon is sitting on the empty wagon

so here we have

$F = (M + 3M) a$

$1.4 M = 4M a'$

so we have

$a' = 0.35 m/s^2$

8 0

3 years ago