Sharping a pencil leaves behind pencil shavings. is sharpening pencil a physical or chemical change

The atoms of a solid aluminum can are close together, vibrating in a rigid structure. if the can is warmed up on a hot plate, what happens to the atoms?

One similarity and one difference between an element and a mixture of elements

If a simple machine aduces the strength of a force, what must be increased? the speed of the input force the work the simple machine performs the size of the simple machine the distance over which the force is applied