PPonte
Sep28-06, 10:30 AM
A 4.00-kg counterweight is attached to a light cord,
which is wound around a spool (refer to Fig. 10.20). The
spool is a uniform solid cylinder of radius 8.00 cm and
mass 2.00 kg. (a) What is the net torque on the system
about the point O? (b) When the counterweight has a
speed v, the pulley has an angular speed v/R. Determine
the total angular momentum of the system about
O. (c) Using the fact that dL/dt and your result
from (b), calculate the acceleration of the counterweight.
For (b) why should we use L = |r \times mv| + I\omega instead of just L = I\omega ?
EDIT: I have just seen why. Sorry.
which is wound around a spool (refer to Fig. 10.20). The
spool is a uniform solid cylinder of radius 8.00 cm and
mass 2.00 kg. (a) What is the net torque on the system
about the point O? (b) When the counterweight has a
speed v, the pulley has an angular speed v/R. Determine
the total angular momentum of the system about
O. (c) Using the fact that dL/dt and your result
from (b), calculate the acceleration of the counterweight.
For (b) why should we use L = |r \times mv| + I\omega instead of just L = I\omega ?
EDIT: I have just seen why. Sorry.