1. force
A force is a push or pull upon an object resulting from the object's interaction with another object.
pull
A pull is a force that acts in the direction of the origin of the force.

2. motion
Motion (physics), any physical movement or change in position or place.
gravity
Gravity is the force that causes two particles to pull towards each other.

3. position speed The point or area occupied by a physical object
Speed is the rate of motion, or equivalently the rate of change in position, often expressed as distance traveled per unit of time.

4. direction
The line or course on which something is moving or is aimed to move or along which something is pointing or facing.
mass

5. lever simple machines wedge lever pulley screw inclined plane
A lever is a simple machine that makes work easier for use; it involves moving a load around a pivot using a force.
simple machines
wedge
lever
pulley
screw
A simple device, such as a lever, pulley, or inclined plane; a machine without moving parts.
inclined
plane
wheel and
axle

6. inclined
plane
pulley

7. wedge
screw

8. Wheel
and axle

9. Light transparent Allowing light to pass through
A range of electromagnetic radiation that can be detected by the human eye
transparent
Allowing light to pass through

10. translucent opaque Allowing only some light to pass through
Not allowing light to pass through

11. Reflection Refraction The bouncing of light off an object
The bending of light as it moves from one material to another

12. Convex lens Concave lens
A lens that is thicker at the center than it is at the edges
Concave lens
A lens that is thicker at the edges than it is at the center

13. prism
A triangular piece of cut glass used to break white light up into its constituent colors.
ROY G. BIV
The color seen in a rainbow: red, orange, yellow, green, blue, indigo, and violet.

14. spectrum
The different colors of light that are coming from a star
Color
The byproduct of the spectrum of light as it is reflected or absorbed

15. rainbow
An arc of colored light in the sky caused by refraction of the sun’s rays by rain
vibration
A quick back-and-forth motion; a trembling motion

16. Sound wave pitch How high or low a sound is
Waves formed by compression of the material (as air) through which they travel regardless of whether they can be heard.
pitch
How high or low a sound is

17. Loud Soft Not loud, harsh or irritating
Marked by intensity or volume of sound
Soft
Not loud, harsh or irritating