Answer:
ω₂ = 93.6 rev / min
Explanation:
ω₀ = 260 rev / min
ω₁ = 0.68*ω₀ = 0.68*(260 rev / min) = 176.8 rev / min
ω₂ = ?
t₁ = 1 min
t₂ = 2 min
We can apply the equation:
ω₁ = ω₀ + α*t₁ ⇒ α = (ω₁ - ω₀) / t₁
⇒ α = (176.8 rev / min - 260 rev / min) / 1 min = - 83.2 rev / min²
then we can use the same formula, knowing the angular acceleration:
ω₂ = ω₀ + α*t₂ ⇒ ω₂ = (260 rev / min) + (- 83.2 rev / min²)*(2 min)
⇒ ω₂ = 93.6 rev / min
Answer:
The value of the electric field is 
Explanation:
We know that the electric field inside a solid cylinder at a distance 
from the centre is given by
Let's consider the cross-section of the cylinder as shown in the figure. Let `O' be the centre of the long solid insulating cylinder having radius 'R'. Also consider that 
be the cetre of the hole of radius 'a' situated at a distance 'b' from 'O'. Given, the volume charge density of the material is 'r'. So, the volume charge density inside the hole will be '-r'. Let's consider 'P' be any arbitrary point inside the hole situated at a distance 's' from .
So, the electric field '
' due to the long cylinder at point 'P' is given by
and the electric field '
'due to the hole at point 'P' is given by
So the net electric field (
) inside the hole is given by
