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emmainna [20.7K]
3 years ago
7

Lifeguards love to spin their whistles. Describe this motion and explain it using angular momentum terminology. Also, please use

complete sentences.

Physics
1 answer:
Dahasolnce [82]3 years ago
4 0

Explanation:

The angular momentum is defined as the product of the moment of inertia of the body and the angular velocity of the object.

In the given problem, Lifeguards love to spin their whistles. The person spins the whistle about  fixed axis by using his fingers.

In this case, the whistle is moving about the fixed axis with the angular velocity. Then there will be angular momentum.

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The Bohr model of the hydrogen atom pictures the electron as a tiny particle moving in a circular orbit about a stationary proto
igor_vitrenko [27]

a) The angular velocity of the electron is 4.12\cdot 10^{16} rad/s

b) The number of revolutions per second is 6.54\cdot 10^{15} rev/s

c) The centripetal acceleration of the electron is 8.98\cdot 10^{22} m/s^2

Explanation:

a)

This is a problem of uniform circular motion: in fact, the electron orbits around the proton in a uniform circular motion.

The angular velocity of an object in uniform circular motion is given by

\omega = \frac{v}{r}

where

v is the linear speed

r is the radius of the trajectory

For the electron orbiting around the proton, we have

v=2.18 \cdot 10^6 m/s

r=5.29\cdot 10^{-11} m

Therefore, the angular velocity is

\omega=\frac{2.18\cdot 10^6}{5.29\cdot 10^{-11}}=4.12\cdot 10^{16} rad/s

b)

The period of revolution of the electron is given by

T=\frac{2\pi}{\omega}

where

\omega = 4.12\cdot 10^{16}rad/s is the angular velocity

Substituting,

T=\frac{2\pi}{4.12\cdot 10^{16}}=1.53\cdot 10^{-16}s

The period is the time the electron takes to make one complete orbit around the proton; therefore, the number of revolutions of the electrons in one second is:

f=\frac{1}{T}=\frac{1}{1.53\cdot 10^{-16}}=6.54\cdot 10^{15} rev/s

c)

The centripetal acceleration of an object in circular motion is

a=\frac{v^2}{r}

where

v is the linear speed

r is the radius of the circle

For the electron, we have

v=2.18 \cdot 10^6 m/s

r=5.29\cdot 10^{-11} m

Therefore, the centripetal acceleration is

a=\frac{(2.18\cdot 10^6)^2}{5.29\cdot 10^{-11}}=8.98\cdot 10^{22} m/s^2

Learn more about circular motion:

brainly.com/question/2562955

brainly.com/question/6372960

#LearnwithBrainly

7 0
4 years ago
Mae prefers to complete graphs or charts to show the information she has learned. What kind of learner is Mae likely to be?
yan [13]

Answer:

Prob. D

Explanation:

I am also a Visual Learner.

3 0
3 years ago
Read 2 more answers
Some kids are playing by rolling a skateboard across level ground beside a 0.75 m high wall. The goal is to drop from the wall v
lys-0071 [83]

Answer:

The speed of the kid and the skateboard together is 0.723 m/s

Explanation:

Let the mass of the kid be m_{k} = 45 kg

Let the mass of the skateboard be m_{s} = 4,5 kg

The initial speed of the skateboard, v_{s} = 8 m/s

The initial horizontal speed of the boy as he jumps on the skateboard, v_{k} = 0 m/s

Let the speed of the kid and the skateboard together be v

According to the principle of conservation of momentum:

m_{k} v_{k} + m_{s} v_{s} = (m_{k} + m_{s}) v

Substituting the appropriate values into  the given equation

(45*0) + (4.5*8) = (45 + 4.8) v

36 = 49.8 v

v = 36/49.8

v = 0.723 m/s

7 0
4 years ago
The mechanical advantage of a simple machine is 3 and its velocity ratio is 4 find its efficiency ​
LiRa [457]

Answer:

75%

Explanation:

Efficiency=MA/VR*100

=3/4*100

=0.75*100

=75%

6 0
2 years ago
Not a question but I’ve noticed a lot of people are replying to questions with a link (xtiny.cf/5GdS) which i’m pretty sure (or
kenny6666 [7]
Like I said. It’s annoying. But I appreciate you doing this for new people.
8 0
3 years ago
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