Name:___________________
Mechanical Arms – Digger & Zigzag Bopper
1. What changes would you make to build a digger that reaches farther but still has the same
motion?
2. If six crossed sticks make the ball of the punching project move forward 12 inches, how
many crossed sticks would you need to make it move forward 24 inches?
3. A first class lever increases the force you put on it if the resistance arm is shorter than the
force arm. Draw this.
4. A first class lever increases the distance you move if the force arm is shorter than the
resistance arm. Draw this.
5. A second-class lever always increases the force. Draw a second class lever lifting a rock.
6.
A third-class lever always increases the distance. Draw a third class lever throwing a rock.
Instructor Notes:
The projects we will build today use levers of different types to move different things. Levers are
simple machines that help us do work. A lever has three main parts: the place where it pivots,
called the fulcrum, the force arm and the resistance arm. The force arm is where the force goes
into the lever and the resistance arm is where the lever pushes on something. The lever can
increase force or increase the distance depending on how it is set up. The fulcrum can be in the
center (a first class lever), or at the ends. When the fulcrum is on the end of the lever, the force
arm can be on the other end (second class lever) or in the middle (third class lever.)
First Class Lever
Second Class Lever
Third Class Lever