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2 years ago

Why is platinum used sparingly in technological applications?

1 answer:

5 0

Platinum is very light and strong alloy, though is has many uses, what prevents is economic consideration, is that platinum is very expensive. It is being in jewelry. Platinum is also used in the chemical industry as a catalyst for the production of nitric acid.silicone benzene. Platinum compounds is also used as important chemotherapy drugs used to treat cancer.

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A particle traveling in a circular path of radius 300 m has an instantaneous velocity of 30 m/s and its velocity is increasing a

grigory [225]

<h2>Answer:</h2>

<h2>Explanation:</h2>

Total acceleration (a) of a particle in a circular motion is the vector sum of the radial or centripetal acceleration ( $a_{C}$ ) of the particle and the tangential acceleration ( $a_{T}$ ) of the particle and its magnitude can be calculated as follows;

a = $\sqrt{(a_{C})^2 + (a_{T})^2}$ ---------------------(i)

$a_{C}$ = $\frac{v^{2} }{r}$ ------------------------------(ii)

Where;

v = instantaneous velocity

r = radius of the circular path of motion

<em>From the question;</em>

v = 30m/s

r = 300m

(i) First let's calculate the centripetal acceleration by substituting the values above into equation (ii) as follows;

$a_{C}$ = $\frac{30^{2} }{300}$

$a_{C}$ = $\frac{900}{300}$

$a_{C}$ = 3m/s²

(ii) From the question, the velocity of the particle is increasing at a constant rate of 4m/s² and that is the tangential acceleration $a_{T}$ , of the particle. i.e;

$a_{T}$ = 4m/s²

(iii) Now substitute the values of $a_{C}$ and $a_{T}$ into equation (i) as follows;

a = $\sqrt{(3)^2 + (4)^2}$

a = $\sqrt{(9) + (16)}$

a = $\sqrt{25}$

a = 5m/s²

Therefore, the magnitude of its total acceleration a, is 5m/s²

5 0

2 years ago

"The drawing shows three layers of different materials, with air above and below the layers. The interfaces between the layers a

My name is Ann [436]

Answer:

Angle of incidence that entered material b= 63.1°

Angle of incidence between a and b = 55.9°

Explanation: Using the formular:

n1sintheta1= n2sintheta2

The light ray which enters material B will be

1.4Sin72.8° = 1.5Sin theta

1.3373= 1.5Sintheta

sintheta = 1.3373/1.5

Sin^-1 0.8916 = Theta

63.1 = theta

When the ray hits interface with material a

1.5Sin63.1 = 1.3 Sin theta

1.3374 = 1.3Sin theta

Sintheta= 1.3374/1.3

Sin theta = 1.0877

There will be total reflection off the boundary b c because sin theta exceeded 1 in value.

The equation should be

1.4sin63.1 = 1.4 sin theta

Sin theta=72.8°

When the ray hits air-c boundary:

1.4sin72.8=1.00sin theta

Sin theta=1.3374/1 =1.3374

There is total reflection.

In material a,the ray will:

1.3sin72.8° = 1.00sin theta

There will be total reflection when the ray hits a-b boundary.

1.3sin72.8= 1.5sintheta

Sin theta= 1.2419/ 1.5

Sin theta =0.8279

Theta= Sin^-10.8279= 55.88°

When ray hits c-air boundary

1.4sin63.1= 1.00sintheta

1.2485= sin theta = Toal reflection.

Therefore when the ray of light pass through the layers of material a, b and c the boundary with air on top and bottom will be total reflection.

7 0

2 years ago

Go to the roller coaster simulation and click on the "launch" button. Pay attention to the pie chart as the roller coaster moves

Paladinen [302]

Answer:

The kinetic energy INCREASES as the roller coaster goes downhill.

Kinetic energy is greatest at POINT 2

Potential energy is greatest at POINT 1

Kinetic energy is decreasing while potential energy is increasing between points 3 AND 4

Which chart comes closest to the relationship between kinetic energy and potential energy at point 6 - CHART OF ANY POINT IN THE SAME HEIGHT AS OF 6

Explanation:

⇒As the potential energy increases , kinetic energy decreases.

⇒Potential energy here is gravitational potential energy.

⇒Thus, more we move away from the centre of the earth , more will be the gravitational potential energy or decrease in kinetic energy

3 0

2 years ago

Read 2 more answers

A stone is thrown into a pond. Five waves were made from the same source in 10 seconds.

lina2011 [118]

Answer:

The Frequency of the wave is 0.2Hertz

The period is 2seconds

Explanation:

We are asked to find the frequency and period

Frequency is the number of oscillations completed in one seconds

If five waves were made from the same source in 10 seconds, hence;

Frequency = number of oscillation/Time

Frequency = 5/10

Frequency = 0.5Hertz

Next is to get the period

Period = 1/Frequency

Period = 1/0.5

Period = 2seconds

3 0

2 years ago

Li is riding her bicycle at 8.0 m/s. She slows down to 4.0 m/s. Her change in velocity is m/s. If Li takes 2 seconds to make thi

forsale [732]

You will have to use this formula:
$v = vo + a \times t$

Final Velocity (V) = 4m/s
Initial Velocity (Vo) = 8m/s
Acceleration (a) = ? m/s^2
Time (t) = 2 secs

Then:

-> 4 = 8 + a x 2
-> 4 - 8 = 2a
-> -4 = 2a
-> a = -4/2
-> a = -2 m/s^2

Ps: It's value is negative because the she was in retrograde motion.

Answer: Her acceleration is -2 m/s^2.

4 0

2 years ago

Read 2 more answers