1. A rod of length 2.5 m is hinged at one end. It starts from rest and swings to the bottom of its arc. Find the speed of the END of the rod when it reches the bottom. The moment of Inertia of a rod that pivots about one end is I = ML^2 /3
it starts 30 degrees above the horizontal (it swings 120 degrees)
the answer is 11 m/s, but how do you get the answer? formula? i have no mass.
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2.
A compact disk of mass .025Kg and radius .080m is spinning freely with an angular velocity of 1000 radians/sec. A bug of mass .0075 kg then lands on the outer edge of the CD and this causes the CD to spin more slowly. Find the angular velocity after the moth lands on the CD. The moment of inertia of a disk is I= mR^2 / 2
the answer is 630 radians/s
using m1v1=m2v2 gets you like 777 radians/s so that is not the proper way, what is the proper way?????
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3.
A rock of mass m = 28kg is tied to the end of a long massless rope of length L = 75m. One end of the rope is tied to the top of the bell tower, and the rock is initially held with the rope horizontal as shown. The rock is then released and swings down to the bottom of the bell tower. Find the tension in the rope just before the rock hits the bottom of the tower.
answer: 820 N.
but why? and how do you get this?
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4.
Two masses (m1 = 12kg and m2 = 18kg) are connected by a string that passes over a pulley. The pulley HAS MASS, with mpulley = 16kg. There is no friction. If the system is released from rest, find the speed of m2 after it has moved a distance of 1.5m (The moment of inertia of the pulley is I = (mpulleyR^2)/2.)
m1 is located on the table m2 is hanging.
how???? i have no clue how to do stuff with pulleys with mass.
the answer is 3.7m/s
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There you have it, you can tell i have som issues with moment of inertia and pendulum type problems, but i really would like to know how to do them.
if you could help it would be appreciated.
it starts 30 degrees above the horizontal (it swings 120 degrees)
the answer is 11 m/s, but how do you get the answer? formula? i have no mass.
------------------------------------------------------------------
2.
A compact disk of mass .025Kg and radius .080m is spinning freely with an angular velocity of 1000 radians/sec. A bug of mass .0075 kg then lands on the outer edge of the CD and this causes the CD to spin more slowly. Find the angular velocity after the moth lands on the CD. The moment of inertia of a disk is I= mR^2 / 2
the answer is 630 radians/s
using m1v1=m2v2 gets you like 777 radians/s so that is not the proper way, what is the proper way?????
----------------------------------------------------------------
3.
A rock of mass m = 28kg is tied to the end of a long massless rope of length L = 75m. One end of the rope is tied to the top of the bell tower, and the rock is initially held with the rope horizontal as shown. The rock is then released and swings down to the bottom of the bell tower. Find the tension in the rope just before the rock hits the bottom of the tower.
answer: 820 N.
but why? and how do you get this?
----------------------------------------------------------
4.
Two masses (m1 = 12kg and m2 = 18kg) are connected by a string that passes over a pulley. The pulley HAS MASS, with mpulley = 16kg. There is no friction. If the system is released from rest, find the speed of m2 after it has moved a distance of 1.5m (The moment of inertia of the pulley is I = (mpulleyR^2)/2.)
m1 is located on the table m2 is hanging.
how???? i have no clue how to do stuff with pulleys with mass.
the answer is 3.7m/s
--------------------------------------------------------------
There you have it, you can tell i have som issues with moment of inertia and pendulum type problems, but i really would like to know how to do them.
if you could help it would be appreciated.
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