Answer:
300 N/m
Explanation:
given,
Load attached to the spring, W = 54 N
length of stretch of the spring, x = 0.15 m
spring constant= ?
Force applied on the spring is calculated by the equation
F = k x
where k is the spring constant
x is the displacement of the spring due to applied load
now,
54 = k × 0.15


hence, the spring constant is equal to 300 N/m
Answer:
Current will be 81.7 mA
Which is not given in bellow option
Explanation:
We have given capacitance 
Resistance R = 500 ohm
Voltage V = 12 volt
We know that time constant of RC circuit of RC circuit is given by

Time is given as t = 1 sec
We know that current in RC circuit is given by

So current 
Which is not given in the following option
Answer: The force does not change.
Explanation:
The force between two charges q₁ and q₂ is:
F = k*(q₁*q₂)/r^2
where:
k is a constant.
r is the distance between the charges.
Now, if we increase the charge of each particle two times, then the new charges will be: 2*q₁ and 2*q₂.
If we also increase the distance between the charges two times, the new distance will be 2*r
Then the new force between them is:
F = k*(2*q₁*2*q₂)/(2*r)^2 = k*(4*q₁*q₂)/(4*r^2) = (4/4)*k*(q₁*q₂)/r^2 = k*(q₁*q₂)/r^2
This is exactly the same as we had at the beginning, then we can conclude that if we increase each of the charges two times and the distance between the charges two times, the force between the charges does not change.
Answer: because they have equal numbers of protons
Explanation: Atoms are electrically neutral because they have equal numbers of protons (positively charged) and electrons (negatively charged). If an atom gains or loses one or more electrons, it becomes an ion