Physics 3

25 July 2022
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of the sciences known as physics, chemistry and biology, the most basic is
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Physics
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The statement "There are regions beneath Earth's Crust that will always beyond reach of scientific investigation is an example of
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Speculation
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A scientific hypothesis may turn out to be right or it may turn out to be wrong, If its a valid hypothesis there must be a test for proving it
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wrong
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A truly educated person is knowledgable about
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science, religion, and the arts
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In Science, A theory is
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a synthesis of a large body of well-tested knowledge
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Science, Art and religion do not contradict one another because
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all three have different domains
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Science and Technology are
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related to one another but not the same thing
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Most Natural phenomena we wonder about
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involve several scientific disciplines
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If experimental findings are not reproducible
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the results are not considered valid
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Technology
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the means of solving a problem by applying the findings of science
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An educated guess is a
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Hypothesis
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An example of scientific hypothesis
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the moon is made of green cheese
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What involves passion, talent and intelligence
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art, music, science, and literature
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In Science, Facts
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may change
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Science
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The collective findings of humans, about nature, and a process of gathering and organizing knowledge about nature
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The graph at the right is a graph of
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an indirect proportion
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Whereas Aristotle relied on logic in explaining nature. Galileo relied on
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experiment
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A kilogram is a measure of an objects?
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Mass
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Compared with a 1.0kg block of solid iron, a 2.0kg block of solid iron has the same
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it doesnt have the same anything, volume, weight and mass.
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Density is the ratio of
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mass to volume
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when a loaf of bed rises, its density
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decreases
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an object is pulled northward with a force of 10N and Southward with a force of 15N. the magnitude of the net force of the object is
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5N
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the force of friction on a sliding object is 10N. The applied force needed to maintain a common velocity is
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10 N
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A man weighing 800N stands at a rest on two bathroom scales so that his weight is distributed evenly on both scales, resting on each scales is
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400N
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A car accelerates from rest at 2m/s2. What is its speed 3s after the car starts moving?
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6m/s
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A ball is thrown upward and caught when it comes back down. In the presence of air resistance, the speed with which it is caught is
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less than the speed it had when thrown upward
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The scientist to first introduce the concept of inertia was
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Galileo
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Which has a greater mass? An automobile battery or a king-sized pillow
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an automobile battery
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Mass(quantity of matter) and Weight (force due to gravity) are
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directly related to each other
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As an object freely falls its
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velocity increases
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The two measurements necessary for calculating average speed are
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distance and time
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Weight is
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the gravitational attraction between you and the earth
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Hang from a pair of gym rings and the upward support forces of the rings will always
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add up equal to your weight
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What is the net force on a box that is being pushed to the left with a force of 40N while its also being pushed to the right with a force of 50N
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10N to the right
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In 2.0 seconds, a car increases its speed from 30 Km/h to 35km/h while a bicycle goes from rest to 4 Kim/h. Which has the greatest acceleration?
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car v1=30 vf=35 5, 5/2=2.5 bike Vi=0 Vf=4 change 4 4/2=2 the car
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A force is a vector quantity because it has been
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magnitude and direction
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Whirl a rock at the end of a string and it follows a circular path. If the String breaks, the tendency of the rock is to
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follow a straight line path
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According to Newton's law of inertia, the result of walking around much of the day is similar to tightening the head of the hammer when its handle hits a solid surface so that we are actually a little bit but shorter in the
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evening
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If an object falls with constant acceleration, the velocity of the object must
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be constant also
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The force that allow you to walk is
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the friction of the floor on your foot and the reaction force of your foot against the floor
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A hockey puck is set in motion across a frozen pond. If ice friction and air resistance are neglected, the force required to keep the puck sliding at constant velocity is
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0.0N
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An object is propelled along a straight-line path in space by a force. If the mass of the object somehow becomes twice as much its acceleration
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halves
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A car has a mass of 1000kg and accelerates at 2m/s2. what is the magnitude of the force exerted on the car
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F=MA F=1000kg*2m/s2 F=2000N
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A heavy object and a light object are dropped at the same time from rest in a vacuum. The heavier object reaches the ground
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at the same time as the lighter object
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A baseball player bats a ball with a force of 1000N. The ball exerts is a reaction force against the bat of
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1000N
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An apple weights 1.0N when held at rest above your head, the net force on the apple is
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0.0N
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A girl pulls on a 10Kg wagon with a constant force of 30N. Neglecting friction, what is the wagon's acceleration in m/s2
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30n/ 10kg 3m/s2
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How much force, or thrust must a 20,000kg jet plane develop to achieve an acceleration of 2m/s2
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F=MA =20,000kg(2) F= 40,000N
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A karate chop delivers a force of 3000N to a board that breaks. The force that the board exerts on the hand is
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3000N
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It is correct to say that impulses is equal to
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the change in momentum
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In order to catch, a ball a baseball player extends the hand forward before impact with the ball and lets it ride backward in the direction of the balls motion upon impact. doing this reduces the force of impact on the player's hand by
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the time of impact is increased
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When a rifle is fired, it recoils so both the bullet and rifle are set in motion, the rifle and bullet ideally acquire equal
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but opposite amounts of momentum
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Whereas impulse involves the time that a force acts, work involves the
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distance that a force acts
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An object that has kinetic energy must be
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moving
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Two objects, A and B have the same size and shape, but A is twice as heavy as B, when they are dropped simultaneously from a tower, they reach the ground at the same time, but A has greater
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Momentum
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Your driving down the highway and a bug splatters on your windshield, which undergoes the greater change in momentum?
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both have the same momentum
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When you jump from an elevated position, you usually bend your knees upon reaching the ground. By doing this, the time of impact is about 10 times more for a stiff-legged landing. In this way the average force your body is experiences is reduced by
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about 10 times
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An object is raised above the ground gaining a certain amount of potential energy, if the same object is raised twice as high it gains
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twice as much potential energy
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A TV set is pushed a distance of 2m with a force of 20N that is in the same direction as the set moves. How much work is done on the set.
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20N*2M=40NM
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In the absence of external work input or output, the energy of a system remains unchanged. Normally energy cannot be created nor destroyed
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True
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A moving object has
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Energy, speed, momentum and Velocity
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The property of a system that enables it to do work
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Energy
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A 4Kg ball has a momentum of 12Kg*m/s what is the ball's speed
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12/4= v=3 M=V/M= 12/M
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Which requires more work: Lifting a 50Kg sack vertically 2m or Lifting a 25Kg sack vertically 4m
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50*10=f m=25*10=f d=2 d=4 500*2 250*4 1000 1000 Both require the same amount of work
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Railroad Car A rolls at a certain speed and collides elastically with railroad car B of the same mass. After the collision, Car A is at rest. How does the speed of Car B after the collision compare with the initial speed of Car A
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the same speed
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An object is raised above the ground gaining a certain amount of potential energy. If the same object is raised twice as high it gains
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twice as much potential energy
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Wind is blowing at 15m/h into rows of wind-powered generators(windmills). What might the wind speed be after it goes through the wind powered generator.
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10m/h
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A 1000kg car and a 2000kg car are hoisted the same distance in a gas station. Raising the more massive car requires
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twice as much work
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According to Newton, the greater the masses of interacting object is
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the greater the gravitational force between them
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If the sun were twice as massive
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the pull on the Earth on the sun would double and the pull on the earth would double
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Earth's Satellites are typically more than 100km high so as above Earths..... Man made satellites such as the space shuttle orbit at altitudes that are above Earth's
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Atmosphere
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Inside a freely falling runaway elevator, your
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apparent weight is zero
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The reason that the mood does not crash into the Earth is that
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the moon has a sufficient tangential speed.
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What is the force of gravity on a 500N women standing on Earth's surface
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500N
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An airplanes flies at 40m/s at an altitude of 50m. The pilot drops a heavy package, which falls and strikes the ground. Where approx does the package land
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beneath the plane
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A projectile is launched vertically at 50m/s. If air resistance is negligible, its speed upon returning to its starting point is
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50m/s
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The force of gravity acts on all apples on an apple tree. Some apples are twice as far as the other. These twice as far as high apples, for the same mass have
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practically the same weight
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A rock is thrown upward at 50 degree with respect to the horizontal. As it rises, its vertical components of velocity
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decreases
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A ball is thrown upward and caught when it comes back down. Neglecting air resistance, how does the speed, just before it is caught compares to the original speed?
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the same as
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Thinking of the inverse-square relationship, how does the thickness of paint sprayed on a surface change when the sprayer is held twice as far away and the sprayed for the same length of time
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1/4 as thick
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What is the force of gravity on a 600N man standing on Earth's Surface
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600N
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A person weighs 150lbs, the Earth is pulling down on that person with a force of 150 pounds. The person is pulling up on the Earth with a force of 150 pound. True or False
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True
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When you whirl an object at the end of a string in a circular path what is the direction of centripetal force that acts on the object?
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Toward the center