The Pulley Lab

The Big Question

• What pattern do you observe regarding the relationship between force and distance in a simple machine?
• How can force be manipulated using a simple machine?

Introduction:

     This week in Physics class we performed a lab that demonstrated the relationship between mass  and the amount of force needed to hold it in place.  This was done using "simple machines" (a clever title since making one was actually very difficult).  We were asked to find how many Newtons were needed to lift .2 kg 10cm in the air without the pulley system.  Then we were asked to do the same thing but with the pulley system.  Each method was supposed to use a certain amount of force.  Without the system took 2 N whereas with it should take about 1.0, and for the challenge .5 N.  Attached are the groups results 

Results: How can force be manipulated using a simple machine?
     Since politics have been my focus for the week, I'm going to answer the big question with an government analogy: the relationship between the mass of an object and the amount of force needed to keep it in place is similar to our system of government, with checks and balances.  The less amount of force needed meant you needed to pull on the string more since you can't receive anything for free in a trade off.  

What pattern do you observe regarding the relationship between force and distance in a simple machine?
     The relationship between the two is inverse.  When the force goes up the distance decreases and when the force goes down the distance increases.

New Key Terms:
     (J) for Joules which is the unit for energy.  J= D(distance)xF(force) which is always constant.  

Real Life Example:
Soccer players are the athletes that use natural simple machines the most; the patella

Without this "pulley" the knee joint isn't demolished and the thigh muscles are able to lift the lower leg.  Thanks to this pulley, society is able to enjoy the best sport in the world; soccer.