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
The length of the pendulum is 3.3 m.
The given parameters:
- Mass, m = 1.5 kg
- Angle, θ = 35⁰
- Speed, v = 3.4 m/s
<h3>What is principle of conservation of energy?</h3>
- The principle of conservation of energy states that, the total energy of a system is always conserved.
P.E = K.E
mgh = ¹/₂mv²
gh = ¹/₂v²
g(L - Lcosθ) = ¹/₂v²
gL(1 - cosθ) = ¹/₂v²

Thus, the length of the pendulum is 3.3 m.
Learn more about length of pendulum here: brainly.com/question/8168512
In paint industry ..and also in steel industry