if i am correct it should be that an atom is made up of three smaller particles and those particles i can see you have written down -Protons which are positive, Neutrons which are neutral and electrons which are negative the neutrons and protons are heavier and stay in the middle of the atom which is called the nucleus hope this helps!!
Let vb be the velocity of the motorboat and let vs be the velocity of the stream.
We know that when she drives upstream the velocity is 8 m/s, in this scenario the velocities point in opposite directions, then we have the equations:

When she drives downstream the velocites point in the same direction then we have the equation:

hence we have the system of equations:

Solving the first equation for the velocity of the boat we have:

Plugging this in the second equation we have:

Therefore, the velocity of the stream is 2 m/s
Answer:
The bystander will hear a frequency of 931.18 Hz.
Explanation:
let V = 39.5 m/s be velocity of the police car and Fs be the frequency a siren of the police car emits. let v = 0 m/s be the velocity of the bystander and Vs = 340 m/s is the velocity of sound in air.
then, we know that the bystander has to hear a higher frequency than the one emitted and the frequency that the bystander hears is given by the doppler relation:
Fo = [(Vs)/(Vs - V)]×Fs
= [(Vs)/(Vs - V)]×Fs
= [(340)/(340 - 39.5)]×(823)
= 931.18 Hz
Therefore, the bystander will hear a frequency of 931.18 Hz.
Answer:
Explanation:
Atoms are the smallest constituent units of matter and they have properties of chemical elements. Atoms can not be broken by any chemical means. Atoms of an elements combine together to form compound. In addition atoms consist nucleus of positively charged protons, neutral neutrons with negatively charged electrons.