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3 years ago

Consider the image above. Vi = the initial velocity and Vf = the final velocity. Is there acceleration? Explain your answer.

Physics

2 answers:

patriot [66]3 years ago

7 0

I just took the quiz, answer is d.

lutik1710 [3]3 years ago

3 0

<span><span>Velocity is a vector, and the initial and final ones are in opposite directions.
There must have been acceleration in order to change the direction of motion.</span>

A) No. The initial and final velocities are the same.
This is all wrong, and not the correct choice.
It's "Yes", and the initial and final velocities are NOT the same.

B) Yes. The ball had to slow down in order to change direction.
This is poor, and not the correct choice.
The "Yes" is correct, but the explanation is bad.
Acceleration does NOT require any change in speed.

C) No. Acceleration is the change in velocity. The ball's velocity is constant.
This is all wrong, and not the correct choice.
It's "Yes", there IS acceleration, and the ball's velocity is NOT constant.

D) Yes. Even though the initial and final velocities are the same, there is a change in direction for the ball.
This choice is misleading too.
The "Yes" is correct ... there IS acceleration.
The change in direction is the reason.
The initial and final velocities are NOT the same. Only the speeds are.
</span>

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A cyclotron is used to produce a beam of high-energy deuterons that then collide with a target to produce radioactive isotopes f

serg [7]

Answer:

19080667.0818 m/s

0.637294 m

$2.1875\times 10^{15}$

Explanation:

m = Mass of deuterons = $3.34\times 10^{-27}\ kg$

v = Velocity

K = Kinetic energy = 3.8 MeV

d = Diameter

B = Magnetic field = 1.25 T

q = Charge of electron = $1.6\times 10^{-19}\ C$

t = Time = 1 s

i = Current = 350 μA

Kinetic energy is given by

$K=\dfrac{1}{2}mv^2\\\Rightarrow v=\sqrt{\dfrac{2K}{m}}\\\Rightarrow v=\sqrt{\dfrac{2\times 3.8\times 10^6\times 1.6\times 10^{-19}}{3.34\times 10^{-27}}}\\\Rightarrow v=19080667.0818\ m/s$

The speed of the deuterons when they exit is 19080667.0818 m/s

In this system the centripetal and magnetic force will balance each other

$\dfrac{mv^2}{r}=qvB\\\Rightarrow \dfrac{mv^2}{\dfrac{d}{2}}=qvB\\\Rightarrow d=\dfrac{2mv}{qB}\\\Rightarrow d=\dfrac{2\times 3.34\times 10^{-27}\times 19080667.0818}{1.6\times 10^{-19}\times 1.25}\\\Rightarrow d=0.637294\ m$

The diameter is 0.637294 m

Current is given by

$i=\dfrac{nq}{t}\\\Rightarrow n=\dfrac{it}{q}\\\Rightarrow n=\dfrac{350\times 10^{-6}\times 1}{1.6\times 10^{-19}}\\\Rightarrow n=2.1875\times 10^{15}$

The number of deuterons is $2.1875\times 10^{15}$

8 0

3 years ago

9. How does water pollution contribute to water shortages?

Grace [21]

Answer:

<h2>if the chemicals seep into the groundwater or in underground aquifers.</h2><h2 />

Explanation:

<h3>One of the largest causes of water scarcity across the world is pollution. ... Pesticides and other fertilizer use by farmers can also lead to water pollution if the chemicals seep into the groundwater or in underground aquifers. The misuse of water resources is another massive issue that leads to water scarcity.</h3>

please love and 5 stars

8 0

3 years ago

What is the mass, in kilograms, of an avogadro's number of people, if the average mass of a person is 150 lb ?

Nikolay [14]

First step is to convert the lb to kg as follows:
1 lb = 0.45 kg
Therefore, 150 lb = 150 x 0.45 = 67.5 kg

Avogadro's number = 6.02 x 10^23

Mass of Avogadro's number of people = 6.02 x 10^23 x 67.5
= 4.0635 x 10^25 kg

5 0

3 years ago

A particle travels along the curve from A to B in 5 s. It takes 8 s for it to go from B to C and then 10 s to go from C to A. De

Elza [17]

Answer:

5.1 m/s

Explanation:

The figure is missing: find it in attachment.

In order to find the average speed, we have to calculate the length of the total path, and divide it by the total time elapsed.

The curve from A to B is a quarter of a circle with a radius of r = 20 m, so its length is:

$AB=\frac{\pi r}{2}=\frac{\pi (20)}{2}=31.4 m$