General Science - Online Test
If mass does not change then acceleration of a particle is dependent on the forces acting upon the particle and the particle's mass. For a given particle, if the net force is increased, the acceleration is increased. For a given net force, the more mass a particle has, the less acceleration it has.
hence the rate of change of momentum of a body is directly proportional to the applied force
On placing a strip of mettallic zinc in an aqueous solution of copper nitrate for about one hour, the copper nitrate solution turns green in colour and zinc strip turns darker.
Formula and Ionic equation for the reaction is as follows.
| Formula Equation: | Zn (s) + Cu(NO3)2 (aq) → Cu (s) + Zn(NO3)2 (aq) |
| Ionic Equation: | Zn (s) + Cu2+ (aq) → Zn2+ (aq) + Cu (s) |
As is seen in ionic equation Zn is loosing 2 electrons, thus oxidation occurs and Cu is gaining 2 electrons, thus reduction occurs. Since oxidation and reduction takes place simultaneously in this reaction, it is a redox reaction. Also since Zn is loosing electrons and becoming darker in colour, it is the reducing agent and Cu is gaining 2 electrons, it is the reducing agent. The resultant solution Zinc nitrate [Zn(NO3)2] is green in colour.
As in the case with DC power, the instantaneous electric power in an AC circuit is given by P = VI, but these quantities are continuously varying. So the average power is given by
Pavg = VI cosφ
where φ is the phase angle between the current and the voltage and where V and I are understood to be the effective or rms values of the voltage and current.
Now RMS value of I is =
So, RMS value of V=
Therefore, Power will be
P= (because cosφ= 1 for circuit containing resistance only)
