Motions and Forces

Physical Science
Motions and Forces

National Standards State Standards SFUSD Standards

B2a* The motion of an object can be described by its position, direction of motion, and speed. That motion can be measured and represented on a graph. 8.1. The velocity of an object is the rate of change of its position.
8.1a. position is defined relative to some choice of standard reference point and a set of reference directions.
8.1b. average speed is the total distance traveled divided by the total time elapsed. The speed of an object along the path traveled can vary.
8.1c. how to solve problems involving distance, time, and average speed.
8.1d. to describe the velocity of an object one must specify both direction and speed.
8.1e. changes in velocity can be changes in speed, direction, or both.
8.1f. how to interpret graphs of position versus time and speed versus time for motion in a single direction.
NOT PRESENT IN SFUSD STANDARDS

B2b* An object that is not being subjected to a force will continue to move at a constant speed and in a straight line. NOT PRESENT IN CA STATE STANDARDS NOT PRESENT IN SFUSD STANDARDS

B2c* If more than one force acts on an object along a straight line, then the forces will reinforce or cancel one another, depending on their direction and magnitude. Unbalanced forces will cause changes in the speed or direction of an object's motion. 8.2. Unbalanced forces cause changes in velocity. As a basis for understanding this concept, students know:
8.2a. a force has both direction and magnitude.
8.2b. when an object is subject to two or more forces at once, the effect is the cumulative effect of all the forces.
8.2c. when the forces on an object are balanced, the motion of the object does not change.
8.2e. when the forces on an object are unbalanced the object will change its motion (that is, it will speed up, slow down, or change direction).
Content Standard 7: Students understand that if more than one force acts upon an object, then the forces can reinforce or cancel one another, depending on their direction and magnitude. Unbalanced forces will cause changes in the speed and/or direction of an object's motion.

NOT PRESENT IN NATIONAL STDS 8.2d. how to identify separately two or more forces acting on a single static object, including gravity, elastic forces due to tension or compression in matter, and friction.
8.2f. the greater the mass of an object the more force is needed to achieve the same change in motion.
8.2g. the role of gravity in forming and maintaining planets, stars and the solar system.
NOT PRESENT IN SFUSD STANDARDS

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9/30/99

National Standards	State Standards	SFUSD Standards
B2a* The motion of an object can be described by its position, direction of motion, and speed. That motion can be measured and represented on a graph.	8.1. The velocity of an object is the rate of change of its position. 8.1a. position is defined relative to some choice of standard reference point and a set of reference directions. 8.1b. average speed is the total distance traveled divided by the total time elapsed. The speed of an object along the path traveled can vary. 8.1c. how to solve problems involving distance, time, and average speed. 8.1d. to describe the velocity of an object one must specify both direction and speed. 8.1e. changes in velocity can be changes in speed, direction, or both. 8.1f. how to interpret graphs of position versus time and speed versus time for motion in a single direction.	NOT PRESENT IN SFUSD STANDARDS
B2b* An object that is not being subjected to a force will continue to move at a constant speed and in a straight line.	NOT PRESENT IN CA STATE STANDARDS	NOT PRESENT IN SFUSD STANDARDS
B2c* If more than one force acts on an object along a straight line, then the forces will reinforce or cancel one another, depending on their direction and magnitude. Unbalanced forces will cause changes in the speed or direction of an object's motion.	8.2. Unbalanced forces cause changes in velocity. As a basis for understanding this concept, students know: 8.2a. a force has both direction and magnitude. 8.2b. when an object is subject to two or more forces at once, the effect is the cumulative effect of all the forces. 8.2c. when the forces on an object are balanced, the motion of the object does not change. 8.2e. when the forces on an object are unbalanced the object will change its motion (that is, it will speed up, slow down, or change direction).	Content Standard 7: Students understand that if more than one force acts upon an object, then the forces can reinforce or cancel one another, depending on their direction and magnitude. Unbalanced forces will cause changes in the speed and/or direction of an object's motion.
NOT PRESENT IN NATIONAL STDS	8.2d. how to identify separately two or more forces acting on a single static object, including gravity, elastic forces due to tension or compression in matter, and friction. 8.2f. the greater the mass of an object the more force is needed to achieve the same change in motion. 8.2g. the role of gravity in forming and maintaining planets, stars and the solar system.	NOT PRESENT IN SFUSD STANDARDS