All categories

3 years ago

Safety precautions taken while determining the melting point of naphthalene using cooling curve

1 answer:

3 0

Answer:What precaution should you take with naphthalene? Briefly explain why there is a constant-temperature plateau in the cooling curve in Figure 1 but not in Figure 2. Briefly explain why, in Figures 1 and 2, the temperature rises immediately after the first crystals appear. If you could only record a single temperature reading in a freezing point determination experiment, which temperature should you record? (This is the point that you should observe most carefully when carrying out the experiment.) Briefly explain why it is important for the beaker of water to cool slowly and for you to stir the naphthalene liquid as it cools.

Explanation:

You might be interested in

Please help in one minute will mark brainlist

azamat

Answer: Different types of telescopes usually don't take simultaneous readings. Space is a dynamic system, so an image taken at one time is not necessarily the precise equivalent of an image of the same phenomena taken at a later time. And often, there is barely enough time for one kind of telescope to observe extremely short-lived phenomena like gamma-ray bursts. By the time other telescopes point to the object, it has grown too faint to be detected.

Explanation: Trust me

8 0

3 years ago

Energy transferred as heat occurs between two bodies in thermal contract when they differ in which of the following properties?

Hatshy [7]

Temperature is the answer

8 0

3 years ago

After polishing his 2-kg wrestling trophy, Mike sets it down on the ground and walks away to find more polish. Meanwhile, Julie

klio [65]

1) The initial momentum of the trophy is zero

2) The initial momentum of the bowling ball is 160 kg m/s

3) The total momentum before the collision is 160 kg m/s

4) The total momentum of the system after the collision is 160 kg m/s

5) The final velocity of the trophy is 32 m/s

Explanation:

The momentum of an object is given by

$p=mv$

where

m is the mass of the object

v is its velocity

In this problem, the data for the trophy before the collision are:

m = 2 kg is the mass

v = 0 is its initial velocity

Therefore, the initial momentum of the trophy is

$p_1=(2)(0)=0$

Using the same equation used in part 1), the initial momentum of the bowling ball is

$p=mv$

where

m is the mass of the bowling ball

v is its initial velocity

The data of the problem are

m = 8 kg is the mass

v = 20 m/s is the velocity

Substituting,

$p_2=(8)(20)=160 kg m/s$

The total momentum of the system before the collision is given by the sum between the initial momentum of the trophy and the initial momentum of the bowling ball:

$p_i = p_1 + p_2$

where

$p_1$ is the initial momentum of the trophy

$p_2$ is the initial momentum of the ball

Here we have

$p_1 = 0$

$p_2 = 160 kg m/s$

Therefore, the total momentum is

$p_i = 0 + 160 = 160 kg m/s$

According to the law of conservation of momentum, for an isolated system (=no external unbalanced forces acting on the system), the total momentum of the system is conserved before and after the collision:

$p_i = p_f$

where

$p_i$ is the total momentum before the collision

$p_f$ is the total momentum after the collision

If we consider the system in the problem to be isolated (i.e. no frictional forces acting on the ball or the trophy), we can therefore say that the total momentum after the collision must be equal to the total momentum before the collision: therefore,

$p_f = 160 kg m/s$

We can write the total momentum after the collision as

$p_f = m_1 v_1 + m_2 v_2$

where:

$m_1 = 2 kg$ is the mass of the trophy

$v_1$ is the final velocity of the trophy

$m_2 = 8 kg$ is the mass of the bowling ball

$v_2 = 12 m/s$ is the final velocity of the ball

Since we also know the value of the final total momentum,

$p_f = 160 kg m/s$

we can solve the equation to find the velocity of the trophy:

$v_1 = \frac{p_f - m_2 v_2 }{m_1}=\frac{160-(8)(12)}{2}=32 m/s$

Learn more about momentum:

brainly.com/question/7973509

brainly.com/question/6573742

brainly.com/question/2370982

brainly.com/question/9484203

#LearnwithBrainly

4 0

3 years ago

Compare the amount of work done when one man uses an ideal pulley to lift a 500 newton weight 2 meters and one man lifts a 500 n

Liono4ka [1.6K]

More work is done when one man lifts the weight using a pulley. Option C is correct.

<h3>What is mechanical advantage ?</h3>

Mechanical advantage is a measure of the ratio of output force to input force in a system, it is used to obtained efficiency of forces in levers and pulley.

It is an effective way of amplify the force in simple machines like lever The theoretical mechanical advantage is defined as the ratio of the force responsible for the useful work in the system to the applied force.

More work is done when one man lifts the weight using a pulley. With the pulley, the mechanical advantage is increasing.

Hence, option C is correct.

To learn more about the mechanical advantage, refer to the link;

brainly.com/question/7638820

#SPJ1

8 0

2 years ago

Newton is said to have been inspired by what to describe the theory of gravity?

maw [93]

Answer:

an apple that fell down from a tree

Explanation:

he wondered what force was acting as the apple fell , he later termed it as a downward force acting on the earth called <em>gravity</em>.

6 0

3 years ago

Safety precautions taken while determining the melting point of naphthalene using cooling curve​

Safety precautions taken while determining the melting point of naphthalene using cooling curve