Forces, Motion, and EnergyPhysics Unit

MA Standard Physical Science11. Explain and give examples of how the motion of an object can be described by its position, direction of motion, and speed.

FME 1.1 Measuring Motion

Speed: the distance traveled divided by the time taken to travel that distance.

S = D/T

average speed = total distance/total time

Velocity

the speed of an object in a direction

Acceleration

the rate that velocity changesincluding speed and/or direction

Circular motion has constant acceleration because direction constantly changes

MA Standard Physical Science1. Differentiate between weight and mass, recognizing that weight is the amount of gravitational pull on an object.

12. Graph and interpret distance vs. time graphs for constant speed.

1.4 Gravity:A Force of Attraction

Gravity: a force of attraction between objects that is due to their masses

Strength depends on mass and distance

Mass: the amount of matter in an object (kilograms or grams)

Law of Universal Gravitation

All objects in the universe attract each other through gravitational force. The size of the force depends on the masses of the objects and the distance between the objects

Gravity increases as mass increases

Gravity decreases as distance increases

Weight

the measure of gravitation force on an object

measured in Newtons (N)

MA Standard Physical Science13. Differentiate between potential and kinetic energy. Identify situations where kinetic energy is transformed into potential energy and vice versa.

5.1 What is energy

the ability to do work

Potential Energy: energy because of position

Gravitational energy=weight x height

Thermal Energy

kinetic energy due to random motion of particles

Chemical Energyex. energy stored in food

released as atoms rearrange

“chemical reactions”

Other forms of energy

Electrical EnergySound EnergyLight EnergyNuclear Energy

5.2 Energy Conversions

Kinetic and Potential Energy

Elastic Potential Energy

Energy Conversion in Plants

Light E → Chemical E → Kinetic EThermal Eenergy used for

processes in cells

Other useful energy conversions

5.3 Conservation of Energy

Energy cannot be created or destroyed but can be changed from one form to another

Most energy is lost through heat (lowest form of energy)ex. lightbulbs, cars,