When you push or pull something, you are applying a force to it. Anything that has mass, especially very large objects like the planet earth, has a force called motion which pulls other objects toward it. Friction is caused when an overall force is applied to an object. If you were to slide a block of wood across the floor, it would eventually stop due to gravity, which opposes the motion of a moving object. A simple machine such as a pulley can decrease friction when lifting heavy objects by using a wheel and a rope. A blank is the path through which electrical blank is allowed to flow. By using a power source, such as a battery, you can build a circuit to convert electricity into other forms of energy like light, sound, or motion. When energy is in a form we can see, it is called light. When light strikes a shiny object like a mirror, it bounces off and travels in a straight line. This is called reflection. Light can also be bent when it travels through different objects and is referred to as its blank. Lenses that refract light outward and are thinner in the middle are called blank. A blank lens refract light inward toward a point and are thicker in the middle. When light strikes something dark and non- reflective, the object will blank the light instead of reflecting it.

Fill in the blanks please with the words:

Refraction. Circuits. concave convex. absorb. current