## Newton's Law

• ME1.1 M to 2M Demo (Air Track)

Uses the frictionless air track (with the PASCO air pump) and 2 strategically placed PASCO photogates. A weight is suspended on one end over a pulley and attached to a mass on the track. The time it takes for the mass to travel between the photogates is measured using the datastudio file "M to 2M.ds" on the demonstration laptop. If the photogates are properly placed, this time will be exactly 3 seconds. Then the same hanging mass is then used to accelerate a cart that has exactly twice the mass of the original. It can be shown that this time should be a factor square root of 2 longer than the previous time (in the limit m << M, where m is the hanging mass, and M is the original cart mass), around 4.24 seconds.

• ME1.2 Ball and Cart

The adjacent figure shows the apparatus. There is a trigger that releases the ball which is constrained to the rails as it falls. Ideally, the ball should remain in the same way. This also demonstrates center of mass principle. Realistically, the cart does not move as much and tends to move in a curved path due to the wheels of the cart. The ball also shoots out of the bottom of the cart and rolls across the room.

• ME1.4 Hero's Engine

This is a steam propulsion system. There are several variations, but the basic idea is to heat water in a flask. Steam produced by the heating water rises and is forced to escape through small tapered tubes with a slight angle. The build up of steam pressure forces the steam through the small orifice with enough force to make the system rotate.

• ME1.6 Sailboat and Fan

A classic Newton's 3rd Law demonstration, in which a sail is placed on a moveable cart, and a fan can be placed on or off the cart. If the fan is on the cart, it will not move.