<span>You are trying to find V2, the formula is V2</span>= <span><span>P1 / </span><span>P2 </span></span>⋅ V<span>1
</span><span>input your numbers, V2</span>= <span><span>90.0kPa / </span><span>20.0kPa </span></span>⋅ 4.0 L to get 18 L
Properties of matter can be broadly classified into two categories:
-Physical properties, these usually involve a change in the state of matter
-Chemical properties. these involve a change in the chemical composition of matter.
Now, physical properties can be further classified as:
Extensive: these depend on the amount of the substance, eg: mass, volume
Intensive: these do not depend on the amount of the substance eg: density, color, melting point, boiling point
A physical property that does not describe a change in state is color. For example: copper sulfate is a compound which is a blue in color. Thus, color provides information which describes the appearance of matter. In contrast, properties like melting or boiling point suggests a change in the state of the substance.
Answer: The correct answer is option(A).
Explanation:
Total forces exerting on the car = F
= Force on car exerting in right direction
= Force on car exerting in left direction
= Force on car exerting in upward direction
= Force on car exerting in downward direction

(negative sign shows the direction)
Since, upward force are equal in magnitude but opposite in direction by which they will balance out each other.so, the net force car will be due to two forces
and 
(negative shows the direction)
The magnitude (size) and direction of the cumulative force acting on the car will 30 N towards right direction.Hence, correct answer is option(A).
Answer:
1) The Kelvin temperature cannot be negative
2) The Kelvin degree is written as K, not ºK
Explanation:
The temperature of an object can be written using different temperature scales.
The two most important scales are:
- Celsius scale: the Celsius degree is indicated with ºC. It is based on the freezing point of water (placed at 0ºC) and the boiling point of water (100ºC).
- Kelvin scale: the Kelvin is indicated with K. it is based on the concept of "absolute zero" temperature, which is the temperature at which matter stops moving, and it is placed at zero Kelvin (0 K), so this scale cannot have negative temperatures, since 0 K is the lowest possible temperature.
The expression to convert from Celsius degrees to Kelvin is:

Therefore in this problem, since the student reported a temperature of -3.5 ºK, the errors done are:
1) The Kelvin temperature cannot be negative
2) The Kelvin degree is written as K, not ºK