Momentum and bar chart representations

[Sam0209]

One day Steve (68 kg) rolls into class on a skateboard. When he rolls in on the skateboard, he and the skateboard move at 2 m/s toward the windows in the room. Steve then jumps off the skateboard and he ends up moving at 1.0 m/s toward the windows of room. How fast and in what direction is the 1 kg skateboard now moving? Be sure to include a momentum bar chart for the situation and a picture with a reference frame.

p=m*v

I tried to draw two different bar charts, one with Steve as the system and one with the skateboard as the system but was unsure of what to do after that.

 

[PhanthomJay]

Try using conservation of momentum with the ground as a reference frame, and please show your solution attempt in accord with PF rules. Thanks.

 

[Ray Vickson]

One day Steve (68 kg) rolls into class on a skateboard. When he rolls in on the skateboard, he and the skateboard move at 2 m/s toward the windows in the room. Steve then jumps off the skateboard and he ends up moving at 1.0 m/s toward the windows of room. How fast and in what direction is the 1 kg skateboard now moving? Be sure to include a momentum bar chart for the situation and a picture with a reference frame.

p=m*v

I tried to draw two different bar charts, one with Steve as the system and one with the skateboard as the system but was unsure of what to do after that.

What on Earth is a "bar chart"? The only bar charts I have ever seen have been for visual presentation of statistical data, and I doubt that is what you want to use in this problem.

 

[CWatters]

I wondered if they mean a stacked bar chart? Two bars (momentum before and after) each bar split to show the momentum of the man and board? Conservation of momentum means both bars are same height. Something like that?

 

[CWatters]

Ok so I wasn't quite right...

 

[PhanthomJay]

It's called 'How to make simple momentum topics complex so you can fail my class"