MindMap Gallery motion and force
Mind map on Chapter 8 of junior high school physics, motion and force, including exploratory experiments, Newton’s first law, balance of two forces, Friction, etc.
Edited at 2024-01-26 11:45:35This infographic, created using EdrawMax, outlines the pivotal moments in African American history from 1619 to the present. It highlights significant events such as emancipation, key civil rights legislation, and notable achievements that have shaped the social and political landscape. The timeline serves as a visual representation of the struggle for equality and justice, emphasizing the resilience and contributions of African Americans throughout history.
This infographic, designed with EdrawMax, presents a detailed timeline of the evolution of voting rights and citizenship in the U.S. from 1870 to the present. It highlights key legislative milestones, court decisions, and societal changes that have expanded or challenged voting access. The timeline underscores the ongoing struggle for equality and the continuous efforts to secure voting rights for all citizens, reflecting the dynamic nature of democracy in America.
This infographic, created using EdrawMax, highlights the rich cultural heritage and outstanding contributions of African Americans. It covers key areas such as STEM innovations, literature and thought, global influence of music and arts, and historical preservation. The document showcases influential figures and institutions that have played pivotal roles in shaping science, medicine, literature, and public memory, underscoring the integral role of African American contributions to society.
This infographic, created using EdrawMax, outlines the pivotal moments in African American history from 1619 to the present. It highlights significant events such as emancipation, key civil rights legislation, and notable achievements that have shaped the social and political landscape. The timeline serves as a visual representation of the struggle for equality and justice, emphasizing the resilience and contributions of African Americans throughout history.
This infographic, designed with EdrawMax, presents a detailed timeline of the evolution of voting rights and citizenship in the U.S. from 1870 to the present. It highlights key legislative milestones, court decisions, and societal changes that have expanded or challenged voting access. The timeline underscores the ongoing struggle for equality and the continuous efforts to secure voting rights for all citizens, reflecting the dynamic nature of democracy in America.
This infographic, created using EdrawMax, highlights the rich cultural heritage and outstanding contributions of African Americans. It covers key areas such as STEM innovations, literature and thought, global influence of music and arts, and historical preservation. The document showcases influential figures and institutions that have played pivotal roles in shaping science, medicine, literature, and public memory, underscoring the integral role of African American contributions to society.
motion and force
Newton's First Law
Explore the effect of resistance on objects
① Let the car slide down the slope of the same height and material
② Use flat surfaces of different materials (such as wooden boards and cotton cloth) to compare the sliding length of the car
③The reason why a moving object stops is because it is affected by resistance. Different materials have different resistances.
The motion of an object does not require force to maintain it
Newton's first law
Content: All objects always remain at rest or move in a straight line at a uniform speed when no force is acted upon.
Based on a large number of empirical facts, generalized through further reasonable reasoning
inertia
All objects have the property of maintaining their original state of motion. In physics, this property of objects is called inertia.
understand
All objects have inertia at any time, and inertia is a property of objects
only about quality
Inertia only has magnitude, no direction
Utilization and prevention of inertia
use
approach
Tighten the hammer head by striking the underside of the hammer handle
precaution
Brake system
airbag
Two Force Equilibrium
balance force
When an object is acted upon by several forces, if it remains at rest or moves in a straight line at a uniform speed, these forces will balance each other.
Equilibrium state: remaining stationary or moving in a straight line at a uniform speed
Conditions for balance of two forces
Explore the conditions for the balance of two forces
① Place the car on a smooth horizontal surface and keep it still
②Add weights to the pallets hanging on both sides of the trolley
③Add unequal weights on both sides and observe the phenomenon
④Add weights with the same mass on both sides and observe the phenomenon
Equal in magnitude, opposite in direction, acting on the same object, acting on the same straight line
application
Skydivers should keep gravity and resistance equal in order to fall at a constant speed
Determine the motion state of an object
Friction Force
definition
Sliding friction: When two objects in contact with each other slide relative to each other, a force generated on the contact surface that hinders relative movement
direction
Parallel to the contact surface of the object and opposite to the direction of relative motion (trend) of the object
conditions for production
Two objects are in contact with each other and have pressure
Rough contact surface
There is relative motion or a tendency of relative motion between two objects
Influencing factors
Explore the influencing factors of sliding friction
① Prepare experimental equipment: three identical wooden blocks, ① ② place them on the wooden board, ③ place them on sandpaper; ② put weights on them; install the same three spring dynamometers on the three wooden blocks
①②: The greater the pressure on the contact surface, the greater the sliding friction.
①③: The greater the roughness of the contact surface, the greater the sliding friction.
Utilization and Prevention of Friction
use
Patterns on the soles and tires of running shoes increase friction with the ground
Apply anti-slip powder on hands before pull-ups and gymnastics exercises
prevent
When the machine is working, the friction of the moving parts will cause wear and tear. Try to reduce the friction.
Sweeping the ice during curling to reduce the roughness of the ice surface