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Brut [27]
3 years ago
5

Have All existing elements have been discovered

Physics
1 answer:
kirill [66]3 years ago
3 0

Answer:

Not not all of the elements have been discovered.

You might be interested in
All atoms of the element potassium have 19 protons. One of the most stable types of potassium atoms has the mass number 39. How
nydimaria [60]
For atoms in the periodic table, the given mass number is the sum of the number of the protons (also called the atomic number) and the number of the neutrons inside its nucleus. Mathematically,
                              mass number = atomic number + number of neutrons
Substituting,
                               39 = 19  + n
                                    n = 39 - 19 = 20
Therefore, the answer is not found in the choices. 
7 0
3 years ago
Read 2 more answers
PLease Help!
scoundrel [369]

Answer:

Option A is the correct answer.

Explanation:

The instantaneous acceleration = Change in velocity in velocity/Time taken

The slope of the graph should give instantaneous acceleration.

 Slope of a graph = Change in value of Y -axis / Change in values of X -axis

 Comparing both the equations

   Change in value of Y -axis = Change in velocity in velocity

   Change in values of X -axis = Time taken

So velocity values should be on the Y axis and Time values should be on the X axis.

Option A is the correct answer.

8 0
4 years ago
A 4.3 kg steel ball and 6.5 m cord of negligible mass make up a simple pendulum that can pivot without friction about the point
Alekssandra [29.7K]

Answer

given,

mass of steel ball, M = 4.3 kg

length of the chord, L = 6.5 m

mass of the block, m = 4.3 Kg

coefficient of friction, μ = 0.9

acceleration due to gravity, g = 9.81 m/s²

here the potential energy of the bob is converted into kinetic energy

m g L = \dfrac{1}{2} mv^2

v= \sqrt{2gL}

v= \sqrt{2\times 9.8\times 6.5}

      v = 11.29 m/s

As the collision is elastic the velocity of the block is same as that of bob.

now,

work done by the friction force = kinetic energy of the block

f . d = \dfrac{1}{2} mv^2

\mu m g. d = \dfrac{1}{2} mv^2

d=\dfrac{v^2}{2\mu g}

d=\dfrac{11.29^2}{2\times 0.9 \times 9.8}

    d = 7.23 m

the distance traveled by the block will be equal to 7.23 m.

8 0
3 years ago
A .422 kg coffee mug rests on a table top 0.63 m above the floor. What is the potential energy of the mug with respect to the fl
kondaur [170]

Answer:

2.61 J

Explanation:

Since potential energy U = mgy where m = mass of object, g = acceleration due to gravity = 9.8 m/s² and y = height of object above the ground.

Now for the coffee mug, m= 0.422 kg and it is 0.63 m on a table, so it is 0.63 m above the ground. Thus, y = 0.63 m.

We compute U

U = mgy

= 0.422 kg × 9.8 m/s² × 0.63 m

= 2.605 J

≅ 2.61 J

So, the potential energy of the mug with respect to the floor is 2.61 J

4 0
3 years ago
Because atoms of elements in the same group of the periodic table have the same number of neutrons, they have similar properties
AURORKA [14]
False. What actually determines the properties of elements are the electrons, or aka valence electrons. They are used to bond, which determines its properties. 
4 0
3 years ago
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