Question

Can anyone explain what's happening in this mechanics problem?

Answer 1

http://i.imgur.com/JL9rFUn.jpg

Answer 2

I'm talking about the first problem.

Answer 3

@dan815

Answer 4

@hartnn

Answer 5

center of mass? @IrishBoy123

Answer 6

omg, I realised pretty late that the rod is horizontally fixed. solved :)

Answer 7

that means the rod can only go up and down ?

Answer 8

yes correct.

Answer 9

may i see the solution ?

Answer 10

i think the rod accelerates when it is in contact with the plank,
then we should be able to find the final speed of the rod when it reaches the height of plank

Answer 11

correct! to determine vertical acceleration of the rod, equate the component of accelerations along the common normal.