<span>If the refrigerator weights 1365 and you are not exerting any vertical force on it, then the normal force is also 1365N. so Fn=1365
Fsf = Static frictional force = (coefficient of static friction) * (Normal force)
So the least for you could exert to move it is equal to the Fsf.
Fsf = (0.49)(1365N)</span><span>
</span>
Answer:
the charge per unit area on the plastic sheet is - 3.23 x 10⁻⁷ C/m²
Explanation:
given information:
styrofoam mass, m = 16 g = 0.016 kg
net charge, q = - 8.6 μC
to calculate the charge per unit area on the plastic sheet, we can use the following equation:

where
the force between the electric field
m = mass
g = gravitational force

where
q = charge
E = electric field
and
E = σ/2ε₀
where
ε₀ = permitivity
thus

mg = qσ/2ε₀
σ = (2mg ε₀)/q
= 2 (0.016) (9.8) (8.85 x 10⁻¹²)/( - 8.6 x 10⁻⁶)
= - 3.23 x 10⁻⁷ C/m²
It’s not Cereal and Milk, carbonated drinks, and smoky air