Answer:
because it is from a mathematical combination of SI base units
Explanation:
The current is defined as the ratio between the charge Q flowing through a certain point of a wire and the time interval,

:

First we need to find the net charge flowing at a certain point of the wire in one second,

. Using I=0.92 A and re-arranging the previous equation, we find

Now we know that each electron carries a charge of

, so if we divide the charge Q flowing in the wire by the charge of one electron, we find the number of electron flowing in one second:
Answer:
The value is 
Explanation:
From the question we are told that
The mass of the car is
The period of the circular motion is 
The radius is 
Generally the frequency of the circular motion is

=> 
=> 
Answer:
Explanation:
A 40kg child throw stone of 0.5kg
At a direction of 5m/s
Recoil can be calculated using recoil of a gun formula
m_1•v_1 + m_2•v_2
m_1•v_1 = -m_2•v_2
The negative sign show that the momentum of the boy is directed oppositely to that of the stone
m_1 Is mass of boy
v_1 is the recoil velocity of the boy
m_2 is mass of stone
v_2 is the velocity of stone
Then,
m_1•v_1 = -m_2•v_2
40•v_1 = -0.5 × 5
40•v_1 = -2.5
v_1 = -2.5 / 40
v_1 = -0.0625 m/s
The recoil velocity of the boy is 0.0625 m/s