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A liquid mixture in which particles can be seen and easily separated by settling or filtration is a...
In a water solution, how do acids differ from bases?
Acids from hydrogen ions (H*),while bases from hydroxide ions (OH-)
When a solid compound dissolves in water...
each of its particles becomes surrounded by water molecules
A measure of how well a solute can dissolve in a solvent at a given temperature is that substance's...
The force that one surface exerts on another when the two rub against each other is called...
When the only forace acting on a falling object is gravity, the object is said to be...
in free fall
The achievement of lifting a rocket off the ground and into space can be explained by...
Newton's third law
Whch of the following is an example of increasing friction intentionally?
throwing sand on an icy driveway
According to Newton's thrid law of motion, when a hammer strikes and exerrts force on a nail, the nail...
exerts an equal force back on the hammer
When you know both the speed and direction of an object's motion, you know the...
velocity of the object
To determine the acceleration rate of an object, you must calculate the change in speed during each unit of...
If speed is measured in kilometers per hour and time is measured in hours, the unit of acceleration is...
kilometers per hour per hour
On a graph showing distance vs. time, a horizontal line represents an object tha is...
not moving at all
If you know the distance an object has traveled in a certain amount of time, you can determine...
the speed of the object
If an object moves in the same direction and at a constant speed for 4 hours, whch of the following is true?
the objects velocity did not change
In an acceleration graph showing speed vs. time, a straight line shows the acceleration is...
If you exert a force of 20 newtons to push a desk 10 metersm how much work do you do on the desk?
What do machines do?
change the amount of force you exert or the distnace over whch you exert the force
Pulling down a rope to hoist a sail on a sailboat is an example of a machine...
changing the direction over whch a force is exerted
The ideal mechanical advantage for an inclined plane is equal to the length of the incline divided by the...
height of the incline
The ideal mechanical advantage of a wheel and axle is equal to the...
radius of the wheel divided by the radius of the axle
In order to do work on an object, the force that you exert must be...
in the same direction as the object's motion
The power of a light bulb that converts electrical energy at a rate of 100 joules per second is...
The number of protons plus the number of neutrons in the nucleus of an atom is called its...
The half-life of a radioactive isotope is the itme it takes for _____ of the radiation in a sample to disappear.
A substance that is present in a solution in a smaller amount and is dissolved by the solvent is called the solute.
Amoung the factors that affect the solubility of a substance are type of solvent, pressure,and time.
Because solubility is a characterisitic property of matter, it can be used to help identify a substance.
The particles in suspension are larger than the particles in a solution but are still too small to be seen easily.
According to Newton's second law of motion, weight depends on an object's mass and the net force acting on the object.
When the only force acting on a falling object is air resistance, the object is said to be in free fall.
Newton's thrid law of motion states that for every action there is an equal but oppostie unbalanced force.
The force that keeps a satellite in Earth's orbit is always directed away from the center of Earth.
If a toy car traveling at 10 cm/s passes a toy car moving at 10 cm/s in the opposite direction, both cars have the same velocity.
A straight line of a graph of speed versus time means that he object has a constant acceleration.
The ideal mechanical advantage of a wheel and axle is the radius of the wheel times the radius of the axle.
Use the pH scale to compare an apple and a lemon.
Lemons have a pH of about 2 and apples have a ph of about 3. A lemon is more acidic.
In terms of pH, explain what would happen if you mixed vinegar with a solution of ammonia?
Vinegar is an acid and ammonia is a base, so neutralization would occur.
What does the pH of drain cleaner tell you about the dangers of such a product?
a high pH means that drain cleaner is very acidic.
How would you describe Kathy's motion? What does such motion mean?
Kathy is jogging at a constant speed. Her speed doesn't change as she moves.
What does the line segment on the graph from 0 to 3 seconds represent? Explain you answer.
The segment represents constant acceleration. The speed increases by the same amount during each second.
What happened to the speed of the ball during the final two seconds?
the ball's speed was constant; it didn't change.
In what class is the direction of the input force opposite to the direction of the output force?
What class of lever is a piar of scissors? Explain your answer.
first-class because the fulcrum is between the input force and the output force.
To which class of lever does each of the following belong? (a) fishing pole; (b) wheelbarrow; (c) bottle opener; (d) pliers?
(a) third; (b) second; (c) second; (d) first
What would happen to the ideal mechanical advantage of the lever in diagram B if the output force were moved further from the fulcrum?
The ideal mechanical advantage would decrease
Why would it be impossible to build machine D?
The machine multiplies both force and distance. The output work of the machine would be greater than the input work, which is impossible because a machine cannot do more output work then input work.
Which machines multiply the input force?
machines 2, 3, 4, and 5, because at least 2 sections of rope support the mass
Which machine has the greatest ideal machanical advantage?
machine 5, because a sections of the rope support the mass
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