PHYSICS-reviewer-first-grading (1).pdf

GENERAL PHYSICS projectile moves in two dimension: horizontal & vertical horizontal “velocity” component (initial horizontal PHYSICS-science that deals with the structure of matter ve...

GENERAL PHYSICS projectile moves in two dimension: horizontal & vertical horizontal “velocity” component (initial horizontal PHYSICS-science that deals with the structure of matter velocity=final horizontal velocity) and interactions between fundamental constituents of the horizontal velocity is constant (gravity does not observable universe. work horizontally to increase/decrease the physics (greek)-concerned with all aspects of nature on velocity) both physikos macroscopic and submicroscopic levels vertical “velocity” component (changes due to gravity) Measurement-finding a number that shows the magnitude and direction change size/amount of something projectile moves up, magnitude decreases, Time-ongoing sequence of events direction upward (vice versa) Weight-amount of matter a thing consist of (heaviness) y-component of acceleration is constant=-g (because g is Length-amount if something measured from one to another always vertical) along the longest side combining this components produce a trajectory that is Capacity-how much quantity a thing can hold parabolic in nature Temperature-how hot or cold a thing is. Metric System-proposed by french astronomer and COMPONENT MAGNITUDE DIRECTION mathematician Gabriel Mouton in 1670 and was horizontal constant constant standardized in Republican France in 1790. vertical changes changes US Standard units are also known as “ENGLISH UNITS” or “US CUSTOMARY UNITS”. CIRCULAR MOTION-motion of particle along a circle Accuracy-how close to the true value a given measurement not necessarily should complete a circle is. even motion along arc is a circular motion Precision-how well a number of independent angles measured clockwise are negative, counterclockwise measurements agree with one another. (specific/exact are positive measurements) Angular displacement-described by radius vector Systematic error-portion of error that remains constant in Right hand rule-fingers are curled to the direction of the same variable (has equal errors) particle, thumb gives direction of the angular displacement ex. blood pressure-using different equipments show vector. different results NEWTON'S LAW OF MOTION accuracy of the measurements isaac newton(1643-1727)-english scientist and non-calibrated instrument cause systematic error mathematician more tricky to track down and often unknown -discovered law of gravity and 3 laws of motion error is often called bias in the measurement 1st law Random error-due to imprecision and can lead to reading -objects in motion tend to stay in motion and objects at above/below the true value. (does not stick to a rule) rest tend to stay at rest unless acted upon by an ex. handspan-people has different hand size unbalanced force. (an object will "keep doing what it's poor technique doing" unless acted upon unbalanced force) can be reduced by use of precise measurements -also called law of inertia Distance INERTIA-tendency of object to resist changes in its state scalar quantity (straight) no direction of motion involved-with magnitude -all objects has inertia total length an object travelled -the heavier the object, the harder it is to change the motion Displacement —things don't keep moving forever because there's almost vector quatity (any direction) with direction and always an unbalanced force acting upon it. magnitude 2nd law: change in position of an object force equals mass times acceleration (F = ma). (always objects at rest (displacement=0) equal) not the same as “distance travelled” -force is directly proportional to mass and acceleration. Speed-distance covered in unit time (constant) (push/pull, strength/energy) the car’s speed is 60 km/hr acceleration-measurement of how quickly an object Velocity-distance traveled in unit time in given direction changes speed (change in velocity) this car has a velocity of 60 km/hr to the west velocity-rate of change in position along with straight line Acceleration-the rate at which an object’s velocity (speed with respect of time is changing over time) -if you double the mass, you double the force change in direction, same speed -if you double the acceleration, you double the force Projectile Motion-any body that is given an initial velocity -doubling mass and acceleration quadruples force and follows a path determined by the effects of (2m)(2a)=4F gravitational acceleration and air resistance. —double mass, constant acceleration - twice the force Limitations: —constant mass, double acceleration - twice the force free fall acceleration is constant and is directed -high mass, low acceleration=great force downward -low mass, high acceleration=great force air resistance is neglected  5. A 0.250 kg cart moving at 0.400 m/s has how much 3rd law: momentum? for every action there is an equal and opposite reaction. (balanced force) a. 0.1 kg-m/s -gravity is pulling you down, your seat is pushing you What is meant by linear momentum? up=balanced force Linear momentum is defined as the product of a system's mass multiplied by its velocity. Work-product of net force acting on a body Give an example of law of conservation of momentum? distance moved in the direction of force A system of gun and a bullet. Before firing the Power-rate at which work is done gun, both the gun and the bullet are at rest, so the Energy-ability to do work total momentum of the system is Zero. As the 2 types: gun is fired, bullet shoots out of the gun and Kinetic-motion (scalar quantity) acquires momentum. To conserve momentum of Potential-stored (energy in position) the system ,the gun recoils.According to the law of conservation of momentum, the total sum of kinetic energy and potential energy in a momentum of the gun and the bullet will be zero system is constant, in absence of friction after the gun is fired. energy cannot be created or destroyed; it may be What is the Newton's second law of motion? transformed from one form to another, but the when a net force acts on a body, it produces total amount of energy in a system remains acceleration in the direction of the net force. The constant. magnitude of this acceleration is directly propotional to the net force acting on the body MOMENTUM-directly proportional to object's mass and inversely propotional to its mass quantity of motion mathematically: F=ma greater mass+greater velocity=greater momentum What is the SI unit of momentum? SI unit=kg ms/Ns The SI unit for momentum is kg m/s and can also product of system’s mass x velocity be expressed as Ns net external force equals change in momentum of a system divided by time Law of Conservation of Momentum: for two objects colliding in an isolated system, the total momentum before and after collision is equal Momentum is inversely proportional to the object's mass and velocity FALSE 2. Momentun is a vector quantity TRUE 3. Momentum can be represented by the symbol 'm' FALSE 4. Einstein stated the second law in terms of momentum FALSE 5 Net forces the total external force applied on a body TRUE 6. The momentum lost by one object is equal to the momentum gained by the other TRUE 7. To every action there is an equal but reverse reaction TRUE MCQs 1. The units for momentum are c. kg-m/s 2. The formula for momentum is b. mass multiplied by velocity 3. The law of conservation of momentum states that, b. p before is the same as p after 4. The difference between a car hitting a wall vs. a car hitting a hay stack is c. the force on the car hitting the hay stack is greater