Please answer as fast as possible

Read the scenario and solve these two problems.

Burka [1]

Answers:

a) 5400000 J

b) 45.92 m

Explanation:

a) The kinetic energy $K$ of an object is given by:

$K=\frac{1}{2}mV^{2}$

Where:

$m=12000 kg$ is the mass of the train

$V=30 m/s$ is the speed of the train

Solving the equation:

$K=\frac{1}{2}(12000 kg)(30 m/s)^{2}$

$K=5400000 J$ This is the train's kinetic energy at its top speed

b) Now, according to the Conservation of Energy Law, the total initial energy is equal to the total final energy:

$E_{i}=E_{f}$

$K_{i}+P_{i}=K_{f}+P_{f}$

Where:

$K_{i}=5400000 J$ is the train's initial kinetic energy

$P_{i}=0 J$ is the train's initial potential energy

$K_{f}=0 J$ is the train's final kinetic energy

$P_{f}=mgh$ is the train's final potential energy, where $g=9.8 m/s^{2}$ is the acceleration due gravity and $h$ is the height.

Rewriting the equation with the given values:

$5400000 J=(12000 kg)(9.8 m/s^{2})h$

Finding $h$ :

$h=45.918 m \approx 45.92 m$

7 0

3 years ago

Read 2 more answers

Explain what happens to the particles in a substance during a physical change.

Bingel [31]

During Physical Change there would be a re-arrangements of atoms or molecules, changes of the arrangement may be change in the distance between atoms or molecules, change in the crystal form, .....etc

for example: water when heated it undergoes a Physical Change and turn into vapor, this means the heat cause the distance between water molecules to increase, so it transferred from the liquid form to the gas form.

NOTE that in Physical Change there is no change in the chemical structure and the material retains all its chemical properties, and no new compounds are produced.

again, A physical change is any change not involving a change in the substance's chemical identity. Matter undergoes chemical change when the composition of the substances changes: one or more substances combine or break up (as in a relationship) to form new substances.Physical changes occur when objects undergo a change that does not change their chemical nature. A physical change involves a change in physical properties. Physical properties can be observed without changing the type of matter. Examples of physical properties include: texture, shape, size, color, odor, volume, mass, weight, and density.

BUT in Chemical Change ( or Chemical Reaction ) there would be change in the chemical nature of the material undergoing a Chemical Change with the production of new compounds.

5 0

3 years ago

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Decision making worksheet answer key

mario62 [17]

Answer:

do your mom hard to get out of the house you doing today no classes are you doing today no classes are you doing today no classes are not sleeping in my bed you have any best to get the meaning do you want for it is my friend I will be there at 12 I have send me a even if we don't ask everyone e for it was a screenshot I am excited everything except you eat your eyes everything except everything else ever even know if everyone e and 10 even though it was kiss emoji everything else ever eyebrows yet I eat early to get enough everything except everything is your class finish up early enough even know what is going on with out hajab I have send it out to edit a video on e a video on each e

Explanation:

7ün go up to the meaning of the name to the class finish it was in the picture of the meaning is F C B you send me your pic of clans go for a walk and 10 even though I am not say that you wake me up

7 0

3 years ago

2. Find the time taken by the bus to reach the stop. need only group B, 2 answer

Molodets [167]

Answer:

t = 2 seconds

Explanation:

In 2nd question, the question is given the attached figure.

Initial speed of the bus, u = 0

Acceleration of the bus, a = 8 m/s²

Final speed, v = 16 m/s

We need to find the time taken by the car to reach the stop. Acceleration of an object is given by :