What Does It Mean to Say Momentum Is Conserved

Question

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What does it mean to say that momentum is conserved?

1 answer:

8 0

Conservation of momentum. So long as no external forces are acting on the objects involved, the total momentum stays the same in explosions and collisions. We say that momentum is conserved. You can use this idea to work out the mass, velocity or momentum of an object in an explosion or collision.

The answer is 0.67 cm³

Explanation:

Density of a substance can be found by using the formula

$Density = \frac{mass}{volume}$

Making volume the subject we have

$volume = \frac{mass}{Density}$

From the question

mass of gold nugget = 13 g

Density = 19.3 g/cm³

Substitute the values into the above formula and solve for the volume

We have

$volume = \frac{13}{19.3}$

= 0.673575

We have the final answer as

0.67 cm³

Hope this helps you

the answer is solid, a liquid has a definitive volume but not shape, and a gas doesnt have a definitive shape nor volume

We can solve this problem by using the equation as shown: A=Aoe^-(ln2/t)T where A is the final amount (0.06 gram), Ao is the initial amount (1g *assumed), t is the half-life (10 years ) and lastly T time elapsed (required). Plug in the values in the equation and you should get 40.5 years and this is approximately 4 half-lives.

3.84 grams is the mass of calcium used in 3 moles of Ca(OH)2 so that it contains the same mass of calcium as the first sample.

Explanation:

Data given:

first sample:

10 grams of Ca3(PO4)2

second sample :

mass of Ca(OH)2 =?

mass of the calcium should be same in both the solutions

In Ca3(PO4)2, 3 moles of calcium is present so

mass = 3 x 40.07 ggrams/mole

mass of calcium= 120.21 grams in Ca3(PO4)2

In Ca(OH)2 only 1 mole of calcium is present so to equal the mass 3 moles should be taken

3 moles of Ca(OH)2 is taken

number of moles of calcium in grams of Ca3(PO4)2

$\frac{10}{310.18}$

= 0.032 moles.

1 mole of Ca3(PO4)2 has 3 moles of calcium

0.032 moles of Ca3(PO4)2 has x moles

$\frac{3}{1}$ = $\frac{x}{0.032}$

= 0.096 moles

so 0.096 moles or 3.84grams of calcium will be used to make solutions of

Ca3(PO4)2 and Ca(OH)2 separately of 10 grams each.

Answer:

D.Lowering the temperature is the best option.

Explanation:

The value of equilibrium constants aren't changed with change in the pressure or concentrations of reactants and products in equilibrium. The only thing that changes the value of equilibrium constant is a change of temperature.

In the reaction below for example;

A + B <==>C+D

If you have moved the position of the equilibrium to the right (and so increased the amount of C and D), why hasn't the equilibrium constant increased?

Let's assume that the equilibrium constant mustn't change if you decrease the concentration of C - because equilibrium constants are constant at constant temperature. Why does the position of equilibrium move as it does?

If you decrease the concentration or pressure of C, the top of the Kc expression gets smaller. That would change the value of Kc. In order for that not to happen, the concentrations of C and D will have to increase again, and those of A and B must decrease. That happens until a new balance is reached when the value of the equilibrium constant expression reverts to what it was before.

What Does It Mean to Say Momentum Is Conserved