Science 421 Physics Physics examines heat sound light

Science 421: Physics

● Physics examines heat, sound, light, energy, motion, forces, and energy with atoms. ● https: //www. youtube. com/watch? v=y. WM KYID 5 fr 8

Rube Goldberg ● https: //www. cbsnews. com/vide o/rube-goldberg-the-father-ofinventions/ (6: 54)

Force (F): ● ● Can be considered a push or a pull Have both a size and a direction Contact and non-contact forces Measured in Newtons (N) Friction: ● A force caused by rubbing between two objects ● This force resists motion. https: //www. youtube. com/watch? v=II 6 h. P 0 Wxle 8 (1: 20)

● Collision ● Friction Contact Forces ● Tension ● Spring

● Nuclear Non-contact Forces ● Gravitational ● Magnetic ● Electrostatic

Balanced vs Unbalanced Forces: Balanced force is when all the forces acting on an object equals zero. This does not produce a change in motion. Unbalanced force is when all the forces acting on an object does not equal zero. This does produce a change in motion.

Mass vs Weight Mass (m): Weight (w): ● A measure of an object’s inertia ● Measured in kilograms (kg) ● The force of gravity acting on a mass. ● Measured in Newtons (N) Inertia: the tendency for an object to keep moving or not start moving. Objects with little mass have small inertia; objects with a large mass have large inertia.

Gravity (g): ● A non-contact force that is the pull that two objects have on each other ● As an object falls to the ground, it picks up speed (acceleration). The force acting on this object is gravity. ● All objects in free-fall on Earth have the same gravitational acceleration which is 9. 81 m/s 2 in the absence of air resistance. Acceleration (a): ● A change in speed or direction ● Speeding up and slowing down are considered acceleration ● Measured in m/s 2

Newton’s First Law An object in motion remains in motion and an object at rest remains at rest unless acted upon by an external force. (Inertia) https: //www. youtube. com/watch? v=Q 0 Wz 5 P 0 Jde. U (5: 50)

Newton’s Second Law The relationship between an object’s mass, its acceleration, and the force applied to an object. F = ma https: //www. youtube. com/watch? v=Wzvhu. Q 5 RWJE (5: 50)

Force = mass x acceleration: ● A small force on a mass results in a small acceleration. A large force on the same mass results in a larger acceleration. If we are to rearrange the formula for acceleration: ● The larger the mass, the lesser the acceleration and the smaller the mass the greater the acceleration.

What is Energy? ● Energy is defined as the capacity to do work. ● Measured in Joules (J) https: //www. youtube. com/watch? v=CW 0_S 5 Yp. YVo (4: 34)

Common Types of Energy ● ● ● ● Nuclear Solar Elastic Electromagnetic Mechanical Gravitational Kinetic

Key Terms: Kinetic Energy: ● Energy of an object due to its motion ● Measured in Joules (J) ● Directly related to its mass and velocity Velocity: the speed and direction of a moving object. How can I increase the kinetic energy of an object?

Key Terms: Gravitational Potential Energy: ● Energy stored by an object ready to be used ● Measured in Joules (J) ● Directly related to its mass and height https: //www. youtube. com/watch? v=Ehx 1 P 4 adv 6 I (1: 22) How can I increase the potential energy of an object?

Conservation of Energy: In a closed system, one where energy cannot enter or leave, the amount of energy remains constant. The energy within this system cannot be created or destroyed but can change form.

The Engineering Design Process https: //www. youtube. com/watch? v=MAhpf. Ft_m. WM (3: 32)

Rube Goldberg ● Born in July 4, 1883 ● Engineer for 6 months designing sewers ● Left engineering to become a cartoonist

What is a Rube Goldberg machine? ‘A symbol of man’s capacity for exerting maximum effort to achieve minimal results. ’

“Simplified” Pencil Sharpener Open window (A) and fly kite (B). String (C) lifts small door (D) allowing moths (E) to escape and eat red flannel shirt (F). As weight of shirt becomes less, shoe (G) steps on switch (H) which heats electric iron (I) and burns hole in pants (J). Smoke (K) enters hole in tree (L), smoking out opossum (M) which jumps into basket (N), pulling rope (O) and lifting cage (P), allowing woodpecker (Q) to chew wood from pencil (R), exposing lead. Emergency knife (S) is always handy in case opossum or the woodpecker gets sick and can't work.

175 step soda machine: https: //www. youtube. com/watch? time_continue=32&v=98 FPril. KJVs (3: 23)