Question: Which of the following is true about scientific models? Select one: A) Models are used to simplify the study of things. B) Computer models are the most reliable kind of model. C) Models explain past, present and future information. D) A model is accurate if it does not change over time.
Answer: <u>A) Models are used to simplify the study of things.</u>
<em>Hope this helps!.</em>
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<em>~A.W~ZoomZoom44</em>
Answer:
Velocity of the electron at the centre of the ring, 
Explanation:
<u>Given:</u>
- Linear charge density of the ring=

- Radius of the ring R=0.2 m
- Distance of point from the centre of the ring=x=0.2 m
Total charge of the ring

Potential due the ring at a distance x from the centre of the rings is given by

The potential difference when the electron moves from x=0.2 m to the centre of the ring is given by

Let
be the change in potential Energy given by

Change in Potential Energy of the electron will be equal to the change in kinetic Energy of the electron

So the electron will be moving with 
This might help and it might not:
Gravitation is the acting force between two bodies. On the other hand, gravity is the force occurring between an object and the very big object earth. Every object with some mass exerts the gravitational force on every other object having some mass. This force and its strength depend on the masses of the objects under consideration. Gravity helps to keep the planets to move in their orbit around the sun.
Gravitation is the force of attraction between any two bodies in the universe. In our universe, each object attracts each other with a certain amount of force. The large distance of separation is the main reason for its weak nature.
Gravity is the weakest type of fundamental force in nature. Still, it holds together the entire solar systems and galaxies.
Gravity has the existence with unlimited range.
Answer:
The kinetic energy of the mass at the instant it passes back through the equilibrium position is 0.06500 J.
Explanation:
Given that,
Mass = 2.15 kg
Distance = 0.0895 m
Amplitude = 0.0235 m
We need to calculate the spring constant
Using newton's second law

Where, f = restoring force


Put the value into the formula


We need to calculate the kinetic energy of the mass
Using formula of kinetic energy

Here, 

Here, 


Put the value into the formula


Hence, The kinetic energy of the mass at the instant it passes back through the equilibrium position is 0.06500 J.