Homework Help: physics

Posted by kate on Wednesday, November 18, 2009 at 4:06pm.

A playground merry-go-round has a disk-shaped platform that rotates with negligible friction about a vertical axis. The disk has a mass of 240 kg and a radius of 1.4 m. A 33- kg child rides at the center of the merry-go-round while a playmate sets it turning at 0.20rpm. If the child then walks along a radius to the outer edge of the disk, how fast will the disk be turning?

physics - bobpursley, Wednesday, November 18, 2009 at 4:55pm
conservation of momentum applies, in this case, angular momentum.

Diskmomentum=I*w
Boy momentum=33*r*2PI*.2/60

set them equal, w will be in rad/sec

disk moment of inertial is 1/2*240*r if you didn't know. Thin disk.
physics - kate, Thursday, November 19, 2009 at 12:07am
the answer has to be in rpm, so does that mean that i'm not supposed to multiply by 2PI/60?

Answer this Question

Related Questions

physics - A playground merry-go-round has a disk-shaped platform that rotates ...
Physics - A playground merry-go-round has a disk-shaped platform that rotates ...
momentum - A playground merry-go-round has a disk-shaped platform that rotates ...
Physics - 1. A certain playground merry-go-round is essentially an 90-kg iron ...
physics - A children's merry-go-round in a park consists of a uniform 200kg ...
College Physics - A 40 kg child is standing on the edge of a merry-go-round in ...
Physics - A large disk of mass M and radius R is spinning like a CD of merry-go-...
physics - A 346 kg merry-go-round in the shape of a horizontal disk with a ...
Physics - A playground merry-go-round made in the shape of a solid disk, has a ...
Physics - A penny is placed at the outer edge of a disk (radius = 0.159 m) that ...

For Further Reading

First Name:
School Subject:
Answer: