On 19 October 2017, we did an experiment to drive deeper into force of the object. Forces is an important part of physic because it helps us understand the phenomenon happen every day. There are four main forces; strong force(Sf), electromagnetic force (EM), weak force(W), gravitational force(g). All this force happen on a small scale so it hard to really study about them. It is simpler to cover it up with new names. Like when you push a block of wood down a ramp your hand EM push the wood block Em and your foot push the ground EM, this type of force called applied force in short. We did an experiment on the roughness of the ramp vs what angle paperclip box slide from the top. In physic, even the roughness of object is defined in number in order to solve for friction. Reversely this experiment is to use the angle of friction to find the roughness of the object.