Question

Learning Goal: To practice Problem-Solving Strategy 7.1 Rotational dynamics problems. Suppose that you are holding a pencil balanced on its point. If you release the pencil and it begins to fall, what will be the angular acceleration when it has an angle of 10.0 degrees from the vertical?

Answer 1

Answer:

when the pencil is balanced on a point it is motionless due to net force only acting trough the center, but when we release the position we are changing the location of a pencil hence due to turning affect it will expericence torque and the angular acceleration produced.

for the complete answer the length and mass of pencil should be known i am giving the general expression for the calculation of angular acceleration

Explanation:

τ=Iα

τ= torque

I = inertia

α= angular acceleration

where

I= mL^2/3 (by geometry of pencil)

when the pencil is released it will experience force due to weight

F=mgsinθ

so τ=Fxd

τ=mgsin(10°)x(L/2)

then.

α=τ/I

α=mgsin(10°)xL/2÷(mL^2)/3