<h2>Answer: A solid mass</h2>
The first atomic model was the one proposed by Jhon Dalton, according to which it is postulated that:
"Matter is made up of <u>indivisible, indestructible and extremely small particles</u> called atoms."
That is, <em>the atom is a </em><u><em>solid and indivisible mass</em></u><em>.</em>
However, over time <u>some limitations were found in Dalton's atomic model </u>and was replaced by the Thomson's atomic model, then by Rutherford's, Bohr's, Sommerfield's, and finally Shrodinger's.
Currently it is known that each atom is composed of a nucleus and one or more electrons attached to the nucleus, which is composed of one or more protons and typically a similar number of neutrons.
In addition, the atomic nucleus is the central part of the atom and concentrates most of the total mass of the atom.
Therefore, the correct option is A.
<span>On the scale the only external forces are the man's weight acting downwards and the normal force which the scale exerts back to support his weight.
So F = Ma = mg + Fs
The normal force Fs (which is actually the reading on the scale) = Ma + Mg
But a = 0
So Fs = Mg which is just his weight.
Fs = 75 * 9.8 = 735N</span>
Answer:
12.88 s
Explanation:
We can solve this problem by considering only the first half the motion, from the moment the ball is projected upward to the moment it reaches its maximum height.
Since this is a uniformly accelerated motion, we can use the following suvat equation:
where:
s is the vertical displacement
v is the final velocity
t is the time
a is the acceleration
Here we have:
v = 0: the vertical velocity is zero when the ball has reached its maximum height, that is
s = 203 m
(acceleration of gravity, negative because it is downward)
Solving the equation for t, we find the time at which the ball reaches the maximum height:
The second half of the motion is symmetrical and identical to the first one, so the total time in air is just twice this time, therefore:
Answer:
Explanation:
As we know by the doppler's effect of light that when source moves with respect to stationary observer then the frequency of light received is different from its actual frequency
the relative change in the frequency of light is given by the formula
here we know that
now we have
Answer:
Gravity
Explanation:
its an invisible force that pulls objects
toward each other.
hope it helps
