My name is lilliannnnnnnn
Molarity and molality both describe the concentration of a substance in terms of moles.
Molarity describes the number of moles of a substance per unit of volume, typically per liter (mol/l).
Molality describes the number of moles per unit of mass, typically kilograms (mol/kg).
When determining the molality of a solution, mol/kg can be obtained by finding the number of moles in the substance, and dividing that number by the the total weight in kilograms of that substance.
When determining the molarity of a solution, mol/l can be obtained by dividing the number of moles in a substance by the total volume in liters of that substance.
The correct answer is they get closer together
Going from gas into a liquid makes the molecules move closer together, which happens again when you turn it into a solid.
Answer:
The kinetic energy remains same and gravitational potential energy increases.
Explanation:
KINETIC ENERGY:
As, we know that the kinetic energy depends upon the speed of the object. Hence, the kinetic energy is given as:
K.E = (1/2)mv²
where,
m = mass
v = speed
K.E = Kinetic Energy
Since, the friction is ignored, therefore the speed of roller coaster will remain same.
Therefore, its Kinetic Energy will also remain same.
POTENTIAL ENERGY:
The potetial energy od a body depends upon its height, as follows:
P.E = mgh
where,
P.E = potential Energy
m = mass
g = acceleration due to gravity
h = height
As, the roller coaster moves up hill its height increases.
Therefore, its potential energy will also increase.
hence, the correct option is:
<u>The kinetic energy remains same and gravitational potential energy increases.</u>
Answer:It started at 20°C, the bras and the iron must b cooled at -150°C.
Explanation:
The formular for linear expansion is given by:
L = Lo + Lo&◇T
Where L = linear dimensions)diameter) after temperature change.
Lo=Original linear dimension
&= Coefficient of thermal expansion for the material.
◇T=Change in temperature.
At some temperature,L(brass)=L(iron)
Lo + Lo&◇T = Lo + Lo&◇T
8.753cm + 8.753cm×(8.7×10^-6C^-1)×◇T=8.753cm+ 8.753cm ×(12.0×10^-6C^-1)×◇T
8.753+(1.636×10^-4)◇T= 8.753+(1.049×10^-4C^-1)◇T
5.87 × 10^-5◇T= 0.010
◇T= 0.010/(5.87×10^-5)
◇T= 170°C
◇T=T1-T2
T= (20 - 170)°C
T= -150°C