## Monday, March 14, 2011

### 3/14 Phet Simulation

Tomorrow there will be a quiz so today is a review.

SD pushed MM on a cart towards the wall and he only moved a few feet and slowly. The harder she pushes, the further MM goes and the faster he gets there. The greater the force the faster the acceleration. The more mass of the object the slower the acceleration. The less smooth the surface the greater the friction, the slower the acceleration. And finally, unbalanced force accelerates while a balanced force goes at a constant rate. Today we'll test all these hypothesises by using Phet.

We tested it by having a little man push a box across a friction-less surface (ice). The harder he pushed, the faster and further the box went. This proves our hypothesis.

Then, the man pushed the box and the refrigerator both with 900 N on ice. The box was moving traveled across the screen in about 3 seconds while it took the refrigerator 5 seconds. This proves our hypothesis that greater masses slow down the acceleration.

The man pushed the box much faster on a friction-less surface (ice) versus wood and the box accelerated faster. We made sure the box was moving at a constant rate of 500 N. This proves our hypothesis.

We will test by pushing a box across the friction-less ice to see if we push it once, how much it accelerates. If there is a balanced force of 0 mph, the box goes at a constant rate. This was proved by us not pushing/touching the box.

This is a picture of the little man pushing the box on a wodden surface with unbalanced forces of 777 N.

JF (4th blog)