Answer:
Electric force on the charge will be equal to -1742000 N
Explanation:
We have given electric field at a point is E = 260000 N/C
And charge q = -6.7 C
We have to find the force on that charge
Force on the charge is equal to Force = charge × electric field ( multiplication of electric field and charge )
So force will be equal to 
So electric force on the charge will be equal to -1742000 N
Answer:
The new pressure of the gas is 15.40 kPa.
Explanation:
Gay-Lussac's law indicates that when there is a constant volume, as the temperature increases, the pressure of the gas increases. And when the temperature is decreased, the pressure of the gas decreases. Mathematically this law indicates that the quotient between pressure and temperature is constant:

On the other hand, Boyle's law says that the volume occupied by a certain gaseous mass at constant temperature is inversely proportional to the pressure. This law is expressed mathematically as:
P*V=k
Finally, Charles's law indicates that as the temperature increases, the volume of the gas increases and as the temperature decreases, the volume of the gas decreases. Mathematically, this law says that when the amount of gas and pressure are kept constant, the quotient that exists between the volume and the temperature will always have the same value:

Combined law equation is the combination of three gas laws called Boyle's, Charlie's and Gay-Lusac's law:

Studying an initial state 1 and a final state 2, it is fulfilled:

In this case:
- P1= 10 kPa
- V1= 200 L
- T1= 0 C= 273 K
- P2=?
- V2= 175 L
- T2= 95 C= 368 K
Replacing:

Solving:

P2= 15.40 kPa
<u><em>The new pressure of the gas is 15.40 kPa.</em></u>
As we know that block of steel is continue to be in moving state
so here the friction must be kinetic friction between two surface
so we know that formula of kinetic friction must be

now we have


now from the above equation we have


So here we need atleast 14.25 N force to continue sliding the box now as per given options all forces which are less than 14.25 N is not correct
Hence correct answer must be 18.0 N
<u>D) 18.0 N</u>
Give the mathematical expression for coulomb's force if q1, q2 are the magnitude of charges and r is the distance between them.
F=K q1q2/r2