# Interactive Physics program broken?

1. Oct 13, 2009

### leatherneckpa

1. The problem statement, all variables and given/known data
I believe there is some kind of glitch in my Interactive Physics program. The screen shot below is supposed to be the result of applying an 8N force at 30º above the horizontal, from the left. My knowledge(?) tells me that a portion of that 8N is going to be expended pushing upward against FG, which would indeed reduce FN, but certainly not to only 2.1N. I also question the acceleration value of 5.1 m/s2. If a portion of the driving force is used to push up against gravity then there is less force to be used for acceleration, and it should be less than the 4.0 m/s2 from a direct horizontal application. Correct?

2. Relevant equations

3. The attempt at a solution
Using a little trig (cos of 30º) I calculated the remainder of the drive force to be 6.928N. Dividing that by the 2kg mass of the block I calculated the acceleration to be 3.464 m/s2 to the right.

2. Oct 13, 2009

### Staff: Mentor

The mass and coefficient of friction don't appear to be shown...

3. Oct 13, 2009

### leatherneckpa

The mass of the block is 2kg, and the plane is frictionless.

4. Oct 13, 2009

### Staff: Mentor

If it's frictionless, then the vertical component does not matter. I get the same acceration answer as you do. Either the program has a bug, or there is something else going on.

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook