physical science test 1

Propose an argument that shows that the earth surface is not flat

1. during a lunar eclipse the darkened portion the moon is curved so artstole indicated that the earth is curved since the object blocking the sun's light from reaching the moon must be curved 2. a ship moving away from the shore gradually disappears the mast (the poles on top of the ship.) of the ship is still visable even though the hulls (the body) of the ship can no longer be seen. also a person standing on top of a hill can still see the ship even though its no lomger visble to the person standing on earth

State Newtons Law of motion an dgive examples

1ST LAW: Law of inertia, where inertia refers to the tendency of an object to resist any change in its state of motion. inertia is measured by measuring an object's mass. EX: would be quckly moving a piece of paper from a bottle of sprite. the bottle remains in an upright position 2ND LAW: an objects motion when a net force does not equal zero. The net force will cause an object to accelerate or decelerate. The rate of acceleration is directly propositional to the magnitude of the net force and inversely proptionl to the objects mass EX: a powerfule engine is required to accelerate a Mercedes while a small engine will be good for a ford escort. 3RD LAW: whenever one objecexerts a force on a second object, the second object exerts an equal but opposite force on the first EX: WHEN A BAT STRIKES A BASEBALL, THE BASEBALL EXERTS AN EQUAL BUT OPPOSITE FORCE ON THE BAT

what is it meant by the term Centripetal force and centrifugal force

Centripetal force: center seeking Centifugal force: moving away from the center

Draw a diagram locating the centripetal force and the centrifugal force

Check the paper

what is the rate of gravitional acceleration near the surface of the earth

Gravitional accleration for all objects in free fall near the surface of the earth is approxiametly 22.2 miles per hour

what does Cognito Ergo Sum

I think therefore i am

define linear momentum amd write th mathematical formula for linear momentum give an example

Linear momentum (p) is defined as the product of an objects mass (m) and its velocity (v) the formula is momentum = mass x velocity. an example would be small car traveling at 30 miles per hour

An object traveling in a circle at a constant speed is the car's velocity also constant

NO; velocity is a vector quantity while speed is a scalar quantity in order for the velocity to be constant both the magnitude ex; speed as well as the direction must be constant therefore if the direction of motion changes then the velocity is not constant

can an object have varying speed if its velocity is constant

NO; velocity is a vector quantity while speed is a scalar quantity in order for the velocity to be constant both the magnitude ex; speed as well as the direction must be constant therefore if the speed changes then the velocity is not constant

prove that the Earth rotates on its axis

Scientist Fucault suspended a large mass from the end of a long wire suspended from the highest point in the Panthenon in Paris, France. once the pendulum is in motion it should continue to move back and forth in straight line. then the object started to swing in a different direction and in fact the end point of its motion eventually traced a circle and it repeated

why a ball thrown horizontally from the top of a bridge and stone drop simultaneously from the same height should strike the ground at the same time

a ball thrown has two independent motions. the verticle part of the motion is affected by gravity while the horizontal motion is not. as a result a ball thrown outward horizontally will hit the ground at the same tume s one dropped at the same time

explain why the term weightless is inappropiate in this instance

a spacecraft in low earth orbit is traveling at 18000 miles per hour- 5 miles per second.However the earths horizon drops 16 feet every 5 miles . therefore the aircraft and everything and everybody in it is in free fall, they are not getting any closer to the surface of the earth since he is in free fall the astronaut believed he or she is weightless

example of a phenomena that can be studied using the scientific method

a student drops a book and a piece of paper at the same time. the students sees that thw book lands before the paper and use the scientific method to explain

why 1 pound object and a 100 pound object dropped at the same time from the same height should strike the ground at the same time assume that air resistance is neglible

according to the 2nd law, an objects rate of acceleration is directly propostional to the magnitude of the objects weight but inversly proptional to the objects mass. so an 100 pound object will have 100 time as mass so would make it slower will the 1 pound will have less mass so it will faster

when viewingk a picture for a short time someone might see an alternate image however another person can see a different image what is this called. scentist face this as well with the rotation of the planets and the sun

conflict of opinon

what is meant be free fall, terminal velocity

free fall occurs when sir resistance on an object is minor and the only force a ting on it is gravity. Terminal velocity is when air resistance is not minor and the object falling will accelerate until the objects weight is balanced by an upward force equal to the objects weight the speed at the point where the forces balance is known as terminal velocity

what happens to the ball if the student suddenly releases it

if the student releases the ball, the ball will initially travel in a straight line tangent to the circle

it is sometimes said that water is removed from clothes in a spin dryer by centrifugal force throwing the water outward. is this correct

if the wall od the spinning cylinder was solid than the inward force that the cylinder exerts on the water

does a car speedometer measure speed, velocity, or both

it measures speed; a speedometer indicated the magnitude but not the direction of the car and velocity is magnitude and direction it has to be speed

wht evidence did newton present in support of this law

newton was able to mathematically derive Kepler's laws by using his laws of motion and universal law of fraitation thus keplers laws which were derived from empirical data could be used to support newton's universal law of gravitation

state the four steps of the scientific method

observing forming a hypothesis experiment results

advantages and disadvantages of the Roman Calender, Julian calender, Gregorian Calender, World calender

roman Calendar advantage: lunar calendar disadvantage: didnt match the seasons Julian Calender advantages: matched seasons and added two more months disadvantages:

difference between scalar and vector

scalar is a quantity that has magnitude but no direction ex: speed, distance, mass vector is a quantity that has both magnitude and direction ex: velocity, acceleration, force

what is science, scientific model, scientific theory, scientific law

science: a branch of knowledge which attempts to explain natural phenomena that can be detated with our senses or by an instrumeny scientific model: an analogy or mental image used to example physical phenomena scientifc theory: a plausible principle offered to explain physcial phenomena a theroy leads to a predication that can be tested scientific law: applied to certain statements that are found to be valid over a large range of observed phenomena

difference between speed and accerlation

speed is a measure of an objects motion s=d/t acceleration is the rate of change of speed in time

Does an apple hanging from a tree exert a gravitational force on the earth?

the force exerted by the apple on the earth must be equal in magnitude to the force exerted by the earth on the apple. According to newton 3rd law, the forces must be equal but in oppposite directions. The earth pulls the apple downward while the apple pulls the earth upward. However only the apple moves if it falls from the tree. this is because of the earth's enormous mass

State newtons universal law of gravitation

the force of gravitational attraction between any two objects the law states that the magnitude of the force between two particles is directly proportional to the product of their masses and inversely proportional to the square of the distance between centers .

which has greater momentum, a sentra traveling at 30 miles per hour or a metro bus traveling at 30 miles per hour

the mass of bus is much greater than the mass of the car the bus has greater momentum

Propose a method to determine length,weight, volume

you can use body parts to help you like thumbs and the length of your arms