Answer: 
Explanation:
Given
mass of laptop m=2 kg
The velocity of car u=8 m/s
The coefficient of static friction is 
The coefficient of kinetic friction is 
As the car is moving, so the coefficient of kinetic friction comes into play
deceleration offered by friction 
Using the equation of motion 
insert the values

Answer:
The voltage will be 0.0125V
Explanation:
See the picture attached
Answer:

Explanation:
As we know that average velocity is defined as the ratio of total displacement of the object and its time interval.
so here we can say

now we know that in one complete revolution the total displacement of the tip of the seconds hand is zero
because it will have same position after one complete revolution from where it starts
so here we can say that the average velocity will be zero

5.4*10^-19 C
Explanation:
For the purposes of this question, charges essentially come in packages that are the size of an electron (or proton since they have the same magnitude of charge). The charge on an electron is -1.6*10^-19
Therefore, any object should have a charge that is a multiple of the charge of an electron - It would not make sense to have a charge equivalent to 1.5 electrons since you can't exactly split the electron in half. So the charge of any integer number of electrons can be transferred to another object.
Charge = q(electron)*n(#electrons)
Since 5.4/1.6 = 3.375, we know that it can not be the right answer because the answer is not an integer.
If you divide every other option listed by the charge of an electron, you will get an integer number.
(16*10^-19 C)/(1.6*10^-19C) = 10
(-6.4*10^-19 C)/(1.6*10^-19C) = -4
(4.8*10^-19 C)/(1.6*10^-19C) = 3
(5.4*10^-19 C)/(1.6*10^-19C) = 3.375
(3.2*10^-19C)/(1.6*10^-19C) = 2
etc.
I hope this helps!
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