Answer:
density is defined as the amount of mass contained in unit volume of a body .its si unit is kg/m*3
Answer:

Explanation:
Electric field in a given region is given by equation

as we know the relation between electric field and potential difference is given as

so here we have


here we know that
and 
so we will have

so we will have

Answer:
Capacitance of the second capacitor = 2C
Explanation:

Where A is the area, d is the gap between plates and ε₀ is the dielectric constant.
Let C₁ be the capacitance of first capacitor with area A₁ and gap between plates d₁.
We have

Similarly for capacitor 2

Capacitance of the second capacitor = 2C
Probably because of the drag coefficient and the density of the liquid.
Answer:multiplying will give us 7 significant figures and addition will give us 3 significant figures
Explanation:
After multiplying the two numbers they resulting value will give a value in its 4 decimal places because both given values are in 2 decimal places. The 4 dp is gotten by the addition of the decimal places of both given numbers (2+2) and
The result of its addition will give us a value in its 1dp and 3 significant figures since the addition of 23.68 and 4.12 will give us 27.8