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2 years ago

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In what way did scientists Jonas Salk and Albert Sabin influence society? They generated plastics for increased manufacturing. T

hey discovered a vaccine to reduce illnesses. They discovered the uses of X-rays to improve patient care. They generated hydroelectric power for cleaner energy.
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2 answers:

faltersainse [42]2 years ago

3 0

They discovered a vaccine to reduce illnesses, specifically Polio and Influenza. The work of Salk and Sabin has almost eradicated what was once a deadly disesase ( polio) . For example, there were 350,000 deaths related to poliovirus across the world in 1988 and they reduced to 22 in 2017. Also, their work has saved millions of lives from polio induced paralysis

max2010maxim [7]2 years ago

3 0

Answer:

B brainliest pleaseeeeeeeee <3

Explanation:

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What component of Star Wars is possible

kolezko [41]

Comparing to current technology, here are some component of star wars that is possible :

- The drones
Remember the flying drones that could shoot stuff in star wars ? we already made that

- Prosthetic limb
Luke's bionic hand in star wars ? we also already made that

- The probe droids
We used a similar thing when our scientist done an expedition to the moon

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2 years ago

Read 2 more answers

A car speeds over a hill past point A, as shown in the figure. What is the maximum speed the car can have at point A such that i

olchik [2.2K]

Answer:

see explanations below

Explanation:

At the point when the car leaves the track, the reaction on the road is zero, meaning that the centrifugal force equals the gravitation force, namely

mv^2/r = mg

Solve for v in SI units

v^2 = gr = 9.81 m/s^2 * 14.2 m = 139.302 m^2/s^2

v = sqrt(139.302) = 11.8 m/s

Answer: at 11.8 m/s (26.4 mph) car will leave the track.

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2 years ago

6.7.1 Current and Current Density A sphere of radius 10 mm that carries a charge of 8 nC =8x 10°C is whirled in a circle at the

aev [14]

Answer:

Part a)

Rate of charge flow is known as electric current

Part b)

Average current flow is

$i = 4\times 10^{-7} A$

Part c)

As we know that current density is current per unit area

$j = 1.27 \times 10^{-3} A/m^2$

Explanation:

As we know that angular frequency of rotation is

$\omega = 100\pi rad/s$

now by basic definition of electric current

Part a)

Rate of charge flow is known as electric current

$i = \frac{dq}{dt}$

so here we have

$i = \frac{Q}{T}$

$i = Qf$

Part b)

here we know that

$\omega = 2\pi f$

$100\pi = 2\pi f$

$f = 50 Hz$

now we have

$i = (8\times 10^{-9})(50)$

$i = 4\times 10^{-7} A$

Part c)

As we know that current density is current per unit area

So we have

$j = \frac{i}{A}$

$j = \frac{4\times 10^{-7}}{\pi(10\times 10^{-3})^2}$

$j = 1.27 \times 10^{-3} A/m^2$

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2 years ago

How many revolutions per minute would a 23 m -diameter Ferris wheel need to make for the passengers to feel "weightless" at the

kirza4 [7]

Answer:

Approximately $6.2\; {\rm rpm}$ , assuming that the gravitational field strength is $g = 9.81\; {\rm m\cdot s^{-2}}$ .

Explanation:

Let $\omega$ denote the required angular velocity of this Ferris wheel. Let $m$ denote the mass of a particular passenger on this Ferris wheel.

At the topmost point of the Ferris wheel, there would be at most two forces acting on this passenger:

Weight of the passenger (downwards), $m\, g$ , and possibly
Normal force $F_\text{normal}$ that the Ferris wheel exerts on this passenger (upwards.)

This passenger would feel "weightless" if the normal force on them is $0$ - that is, $F_\text{normal} = 0$ .

The net force on this passenger is $(m\, g - F_\text{normal})$ . Hence, when $F_\text{normal} = 0$ , the net force on this passenger would be equal to $m\, g$ .

Passengers on this Ferris wheel are in a centripetal motion of angular velocity $\omega$ around a circle of radius $r$ . Thus, the centripetal acceleration of these passengers would be $a = \omega^{2}\, r$ . The net force on a passenger of mass $m$ would be $m\, a = m\, \omega^{2}\, r$ .

Notice that $m\, \omega^{2} \, r = (\text{Net Force}) = m\, g$ . Solve this equation for $\omega$ , the angular speed of this Ferris wheel. Since $g = 9.81\; {\rm m\cdot s^{-2}}$ and $r = 23\; {\rm m}$ :

$\begin{aligned} \omega^{2} = \frac{g}{r}\end{aligned}$ .

$\begin{aligned} \omega &= \sqrt{\frac{g}{r}} \\ &= \sqrt{\frac{9.81\; {\rm m \cdot s^{-2}}}{23\; {\rm m}}} \\ &\approx 0.653\; {\rm rad \cdot s^{-1}} \end{aligned}$ .

The question is asking for the angular velocity of this Ferris wheel in the unit ${\rm rpm}$ , where $1\; {\rm rpm} = (2\, \pi\; {\rm rad}) / (60\; {\rm s})$ . Apply unit conversion:

$\begin{aligned} \omega &\approx 0.653\; {\rm rad \cdot s^{-1}} \\ &= 0.653\; {\rm rad \cdot s^{-1}} \times \frac{1\; {\rm rpm}}{(2\, \pi\; {\rm rad}) / (60\; {\rm s})} \\ &= 0.653\; {\rm rad \cdot s^{-1} \times \frac{60\; {\rm s}}{2\, \pi\; {\rm rad}} \times 1\; {\rm rpm} \\ &\approx 6.2\; {\rm rpm} \end{aligned}$ .

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1 year ago

A sound wave traveling eastward through air

vagabundo [1.1K]

1 - Vibrate east and west

Sound waves are <em>longitudinal waves</em>, that means the vibrations are parallel to the direction of energy transfer. If the energy transfer is going East, then the vibrations will be East and West creating compressions and rarefactions in the air.

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2 years ago