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3 years ago

Which statement describes a scientific theory?

Physics

1 answer:

Mekhanik [1.2K]3 years ago

6 0

Answer:

A theory changes based on new observations and testing.

Explanation:

The first statement here refers to a law. A law states how something behaves without providing an explanation to such observations.

Scientific theories are explanation into a phenomenon. They give reasons to why certain patterns are noticeable.

They are based on multiple tests and validation of a hypothesis. By so doing, they can be changed based on new observations and testing.

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What are examples of chemical energy

klio [65]

-- the big flash of light and heat coming out of the head
of a match when it gets hot enough;

-- the explosion of a tiny bit of gunpowder that can send
a bullet many miles;

-- the energy captured from a few drops of burning gasoline
that moves a car;

-- the energy in the carbohydrates you eat that is used
to move you around;

3 0

3 years ago

An object that is falling has the following type(s) of energy. Ignore air resistance.

Anton [14]

Potential and kinetic

6 0

2 years ago

Read 2 more answers

Find the angle formed by two forces of 7N and 15N respectively if its result is worth 20N

nadezda [96]

First, you need to make certain assumptions before solving this question. Why? Because there are no information given about the direction of these forces. In such questions as above, ALWAYS make the following assumptions:

1) Take first force, say $F_{1}$ , and assume that it is pointing towards the x-direction.

Let us take the 7N force! By keeping the above assumption in our minds, the force vector would be like:
$F_{1}$ = $7i$ , where $i$ = Unit vector in the x-direction.

2) Take the second force, say $F_{2}$ , and assume that it is making an angle $\alpha$ with the first force $F_{1}$ .

Let us take the 15N force! By keeping the above assumption in our minds, the forces vector would be like:

$F_{2} = (15*cos \alpha)i + (15*sin \alpha )j$

Now from simple vector addition, we know that,
$F_{R} = F_{1} + F_{2}$ --- (A)

Where $F_{R}$ = Resultant vector.
NOTE: In equation (A), all forces are in vector notation. Assume that there is an arrow head on top of them.

Let us find $F_{1}+F_{2}$ first!
$F_{1}+F_{2}$ =   $7i+(15*cos \alpha)i + (15*sin \alpha )j$

=> $F_{1}+F_{2}$ =   $(7+15*cos \alpha)i + (15*sin \alpha )j$

Now the magnitude of $F_{1}+F_{2}$ is,
| $F_{1}+F_{2}$ | = $\sqrt{ (7+ 15*cos \alpha)^{2} + (15*sin \alpha )^{2}}$

=> | $F_{1}+F_{2}$ | = $\sqrt{ 49 + 225*(cos \alpha)^{2} + 210*(cos \alpha)+ 255*(sin \alpha )^{2}}$

Since $(sin \alpha)^{2} + (cos \alpha)^{2} = 1$ , therefore,

=> | $F_{1}+F_{2}$ | = $\sqrt{ 49 + 225 + 210*(cos \alpha)}$

Since  | $F_{1}+F_{2}$ | = | $F_{R}$ |, and the magnitude of the resultant force is 20N, therefore,

| $F_{R}$ | = | $F_{1}+F_{2}$ |
20 = $\sqrt{ 49 + 225 + 210*(cos \alpha)}$

Take square on both sides,
400 = $49 + 225 + 210*(cos \alpha)$
$(cos \alpha) = \frac{3}{5}$

$\alpha = 53.13^{o}$

Ans: Angle formed by the two forces, 7N and 15N, is: 53.13°

-israr

4 0

2 years ago

What is the acceleration due to gravity in a region where a simple pendulum having a length 75.000 cm has a period of 1.7357 s?

Ksju [112]

Answer:

Explanation:

T = 2π $\sqrt{L/g}$

(T / 2π)² = L/g

g = 4π²L/T²

g = 4π²(0.75000)/(1.7357)²

g = 9.82814766...

g = 9.8281 m/s²

6 0

2 years ago

Calculate the current passing through a conductor of resistance 4ohms. If a potential difference of 15V its ends______

statuscvo [17]

Explanation:

current = velocity/resistance

I = V/R

15/4

current = 3.75A

hope this helps...

6 0

2 years ago