Answer:
Thomson's model showed an atom that had a positively charged medium, or space, with negatively charged electrons inside the medium. After its proposal, the model was called a "plum pudding" model because the positive medium was like a pudding, with electrons, or plums, inside.
KE = 1/ 2 * 1252 * 144
as KE = 1/2 * m * v ^2
= 90144 J
Answer:
The initial velocity was 9.39 m/s
Explanation:
<em>Lets explain how to solve the problem</em>
The ball is thrown straight upward with initial velocity u
The ball reaches a maximum height of 4.5 m
At the maximum height velocity v = 0
The acceleration of gravity is -9.8 m/s²
We need to find the initial velocity
The best rule to find the initial velocity is <em>v² = u² + 2ah</em>, where v is
the final velocity, u is the initial velocity, a is the acceleration of
gravity and h is the height
⇒ v = 0 , h = 4.5 m , a = -9.8 m/s²
⇒ 0 = u² + 2(-9.8)(4.5)
⇒ 0 = u² - 88.2
Add 88.2 to both sides
⇒ 88.2 = u²
Take square root for both sides
⇒ u = 9.39 m/s
<em>The initial velocity was 9.39 m/s</em>
Answer:
An object at rest does not move and an object in motion does not change its velocity, unless an external force acts upon it
Explanation:
This statement is also known as Newton's first law, or law of inertia.
It states that the state of motion of an object can be changed only if there is an external force (different from zero) acting on it: therefore
- If an object is at rest, it will remain at rest if there is no force acting on it
- If an object is moving, it will continue moving at constant velocity if there is no force acting on it
This phenomenon can be also understood by looking at Newton's second law:
F = ma
where
F is the net force on an object
m is the mass
a is the acceleration
If the net force is zero, F = 0, the acceleration of the object is also zero, a = 0: therefore, the velocity of the object does not change, and it will continue moving at the same velocity (which can be zero, if the object was at rest).
Answer:
the branch of science concerned with the nature and properties of matter and energy. The subject matter of physics, distinguished from that of chemistry and biology, includes mechanics, heat, light and other radiation, sound, electricity, magnetism, and the structure of atoms.
