The photoelectric effect proved:

Substances that cannot be broken down into other substances are called __________. -compounds -protons -neutrons -elements

denpristay [2]

Answer:

Substances that cannot be broken down into other substances are called elements.

Explanation:

Elements are pure substances that cannot be broken down into other elements through any non-nuclear means. For example: hydrogen, helium, lithium, beryllium, boron, and carbon.

A list of the elements can be found in a periodic table.

5 0

4 years ago

A plane leaves the airport in Galisteo and flies 160 km at 66.0 ∘ east of north; then it changes direction to fly 260 km at 49.0

user100 [1]

<u>The question doesn't have any particular requirement, but we'll compute the displacement of the plane from its initial and final landing point in the pasture </u>

Answer:

$\displaystyle |\vec{r}|=321.464\ km$

$\displaystyle \theta =-19.395^o$

Explanation:

<u>Displacement </u>

The vector displacement $\vec r$ is a measure of the change of position of a moving object. The displacement doesn't depend on the path followed, only on the final and initial positions. Its scalar counterpart, the distance, does measure the total space traveled and considers all the changes in the direction taken by the object. To find the displacement, we must add all the particular displacements by using vectors.

The plane first flies 160 km at 66° east of north. To find the vector expression of this displacement, we must know the angle with respect to the East direction or North of East. Knowing the angle East of North is 66°, the required angle is 90°-66°=34°

The first vector is expressed as

$\displaystyle \vec{r_1}=\left \langle 160^o\ cos34^o, 160\ sin34^o \right \rangle$

$\displaystyle \vec{r_1}=\left \langle 132.646, 89.471 \right \rangle$

The second displacement is 260 km at 49° South of East. This angle is below the horizontal respect to the reference, thus we use -49°.

The second vector is expressed as:

$\displaystyle \vec{r_2}=\left \langle 260\ cos(-49^o), 260\ sin(-49^o)\right \rangle$

$\displaystyle \vec{r_2}=\left \langle 170.575,-196.224\right \rangle$

The total displacement is computed as the vectorial sum of both vectors

$\displaystyle \vec{r}=\vec{r_1}+\vec{r_2}=\left \langle 132.646+170.575\right \rangle+ \left \langle89.471-196.224\right \rangle$

$\displaystyle \vec{r}=\left \langle 303.221,-106.753\right \rangle\ km$

The magnitude of the total displacement is

$\displaystyle |\vec{r}|=\sqrt{303.221^2+(-106,753)^2}$

$\displaystyle |\vec{r}|=321.464\ km$

And the direction is

$\displaystyle tan\ \theta =\frac{-106.753}{303.221}=-0.352$

$\displaystyle \theta =-19.395^o$

6 0

3 years ago

What times what equals 400

Radda [10]

If you're willing to consider fractions or decimals,
then there are an infinite number of answers.
Like (2.5 x 160), and (15 x 26-2/3).

If you want to stick to only whole numbers,
then these 8 combinations do:

1, 400
2, 200
4, 100
5, 80
8, 50
10, 40
16, 25
20, 20

7 0

4 years ago

What clues should you look for to determine if an authors purpose is to make you think deeply

8090 [49]

If the context is difficult to understand they want you to think hard to get what their trying to say and make you feel a certain way.

7 0

3 years ago

A 0.500-kg mass suspended from a spring oscillates with a period of 1.36 s. How much mass must be added to the object to change

lord [1]

The mass that must be added is 0.628 kg

Explanation:

The period of a mass-spring system is given by