Answer: Properties and States of Matter Practice
1. Which of the following are pure substances? Compounds
2. A substance that cannot be broken into similar substances is called a(n)... Element
3. When a physical change in a sample occurs, which of the following does NOT change? Composition
4. Which of the following will cause a decrease in gas pressure in a closed container? Lowering the temperature
5. The heat of fusion for water is the amount of energy needed for water to... Melt
6. The phase change in which a substance changes from a gas directly to a solid is... Deposition
7. Which of the following phase changes is an exothermic change? sublimation
8. Which of the following has the highest viscosity? Corn Syrup
9. In which of the substances in the figure below are the forces of attraction among the particles so weak that they can be ignored under ordinary conditions? It is the one where the particles are more apart.
Explanation:
Answer: 3MW
Explanation:
W = 1/2 mv^2
W = 0.5 x 1200 x 25^2 = 375 kW
T = 8s
P= 335 x 10^3 x 8 = 3,000 kW = 3MW
890 m/s 850 m/s 790 m/s 895 m/s 870 m/s
Car A
Car B
Car C
Car D
Car E
The mass of each car is the same so car D will take the longest time to come to a full stop. Hence, option D is correct.
In mechanics, acceleration is a unit used to describe how quickly the velocity of an object varies in relation to time. The direction of the net force acting on an object determines its acceleration.
Since acceleration has both a magnitude and a direction, it is a vector quantity. Velocity is another vector quantity. Acceleration is defined as the change in velocity vector over a time interval divided by the time interval.
According to the question, we want to determine which automobile will take the longest to fully stop because we know that each one has the same mass and the same velocity. Here, we can assume that all the vehicles slow down uniformly, thus the vehicle traveling at the maximum speed will take the longest to come to a complete stop.
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Answer: Car D.
Explanation:
We know that each car has the same mass, and knowing the velocity of each car, we want to know which car will require the longest time to come to a full stop. Here we may assume that all the cars decelerate at the same rate, so the car with the highest speed is the car that will take the longest income to a full stop.
The answer is car D, which velocity is 895 m/s.
Answer:Explain the symbols.
Explanation: Because it shows you what it is.
The law of thermodynamics is that the heat transfers from a hot object to a cold one. This is how the heat gradient goes. An ice can transfer heat when it is in contact with an object which is lower in temperature. For example when ice cube touches an object of temperature -50 degree Celsius.
Answer:
Transfer of heat occurs when there is difference in the temperatures of two bodies. The temperature indicates hotness or coldness of a body. With even small difference in temperature, heat transfer occurs from hotter to the colder one till both of them achieve thermal equilibrium.
So, an ice-cube can transfer heat to another ice-cube if its temperature is higher than another. Suppose, the temperature of ice cube 1 is 0°C and another one is at -10°C, heat transfer would occur.
The correct answer is B) Conductor
A conductor is a material that allows for the flow of electrical charge (electrical current). This type of material provides little or no resistance to the flow of electric current. This is due to the fact that these type of materials have free electrons which conduct the flow of electrical current in any direction.
Different types of conductors have different resistances. Some types of materials are good conductors whereas some are not so good.
Some common conductors are Copper, gold, silver and aluminium.
An insulator is the an object of type of material which have a strong resistance to the flow of electric current. Some common insulators are glass, wood and plastic.