experimental technique

[skin]

Monitoring the height a ball gains in an air jet.

Using Ping-Pong Balls and I'd like to keep the air jet velocity (20ms) while varying the mass of the ball.

The ball is currently 2g, I'm looking to add another gram to this figure. I thought about paint, does anybody have any other suggestions ?

I'm aware that this will possibly disregard the results acheived with the ball measured at 40mm diameter because paint will increase the diameter but I can't think of other methods that could increase mass without varying diameter.

[?]

[nbo10]

Use hollow sphere's and vary the ID.

JMD

[skin]

ID ?

[cookiemonster]

Internal diameter.

cookiemonster

[skin]

ta :)

[skin]

I suppose I could also use a squash ball, I'd imagine a 20ms air jet will provide enough upward force to allow the ball to gain and maintain a height.

I'd expect the squash ball to gain less height than the ping pong ball. What equation could I use to describe this height difference?

F=ma ? Assuming both balls had the same diameter the upward force acting on both the balls would be equal but obviously the downward force will increase due to more mass ?

Also any other ideas for balls to be used? Its surely very important that the different balls have an equal diameter?