Homework Help: PHYSICS

Posted by cindy on Wednesday, March 14, 2012 at 1:55pm.

A weather vane initially at rest has a moment of inertia of 0.115 kg · m2 about its axis of rotation. A 44.5 g piece of clay is thrown at the vane and sticks to it at a point 10.5 cm from the axis. The initial velocity of the clay is 18.5 m/s, directed perpendicular to the vane. Find the angular velocity of the weather vane just after it is struck.

PHYSICS - Elena, Wednesday, March 14, 2012 at 2:25pm
The moment of inertia of weather vane with piece of clay is
I = I(vane) +mR^2 = 0.115+44.5•10^-3•(0.105)^2=
= 1.2•10^-2 kg • m2.
The torque due to the clay hitting is M=F•R
F•t=Δp=m•v, therefore F=m•v/t.
Then M=F•R=m•v•R/t.
From Newton’s 2 Law for rotation M=I• ε.
m•v•R/t =I•ε.
m•v•R/I= ε• t = ω
ω = m•v•R/I ==44.5•10^-3•18.5•0.105/1.2•10^-2= 7.21 rad•s

Answer this Question

Related Questions

physics - A weather vane initially at rest has a moment of inertia of 0.119 kg &...
physics - A weather vane initially at rest has a moment of inertia of 0.119 kg &...
physics - Four objects are held in position at the corners of a rectangle by ...
Physics Please help! - In each of the following cases, the mass is 7.99 kg and ...
Physics Please help! - In each of the following cases, the mass is 7.99 kg and ...
Physics - Four particles in the xy plane have the following masses and ...
physics - An ice skater spins about a vertical axis at an angular speed of 15 ...
Physics - A nonuniform 2.0-kg rod is 2.0 m long. The rod is mounted to rotate ...
physics - Suppose that you measured the moment of inertia of the system as I = 5...
physics - A thin non-uniform rod of length L=2.00 m and mass M=9.00 kg is free ...

For Further Reading

First Name:
School Subject:
Answer: