How much energy or stopping power is needed to bring a car to a stop from 100 mph?

A CD spins at a constant angular velocity of 5.0 revolutions per second clockwise.

Lera25 [3.4K]

The true statement about the CD is:

<h3><em>b. No net torque acts on it at all.</em></h3>

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<h3>Further explanation</h3>

Centripetal Acceleration can be formulated as follows:

$\large {\boxed {a = \frac{ v^2 } { R } }$

<em>a = Centripetal Acceleration ( m/s² )</em>

<em>v = Tangential Speed of Particle ( m/s )</em>

<em>R = Radius of Circular Motion ( m )</em>

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Centripetal Force can be formulated as follows:

$\large {\boxed {F = m \frac{ v^2 } { R } }$

<em>F = Centripetal Force ( m/s² )</em>

<em>m = mass of Particle ( kg )</em>

<em>v = Tangential Speed of Particle ( m/s )</em>

<em>R = Radius of Circular Motion ( m )</em>

Let us now tackle the problem !

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<em>Complete Question:</em>

<em>A CD spins at a constant angular velocity of 5.0 revolutions per second clockwise. Which of the following statements about the CD is true?</em>

<em>a. A net torque acts on it clockwise to keep it moving</em>

<em>b. No net torque acts on it at all.</em>

<em>c. A net torque acts on it counterclockwise to keep it moving</em>

<u>Given:</u>

angular velocity = ω = 5.0 revolutions per second

<u>Asked:</u>

net torque = Στ = ?

<u>Solution:</u>

Constant angular velocity → angular acceleration = α = 0 rad/s²

$\Sigma \tau = I \alpha$

$\Sigma \tau = I (0)$

$\Sigma \tau = 0 \texttt{ Nm}$

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<h3>Conclusion:</h3>

The true statement about the CD is:

<em>b. No net torque acts on it at all.</em>

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<h3>Learn more</h3>

Impacts of Gravity : brainly.com/question/5330244
Effect of Earth’s Gravity on Objects : brainly.com/question/8844454
The Acceleration Due To Gravity : brainly.com/question/4189441

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<h3>Answer details</h3>

Grade: High School

Subject: Physics

Chapter: Circular Motion

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Keywords: Gravity , Unit , Magnitude , Attraction , Distance , Mass , Newton , Law , Gravitational , Constant

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8 0

3 years ago

An electromagnetic wave has a frequency of 4.0 x 10^18 Hz. What is the wavelength of the wave?

LenaWriter [7]

Answer:

7.5 × 10^-11 m

Explanation:

Hope this helps !

3 0

3 years ago

Read 2 more answers

A 8.00-kg object is hung from the bottom end of a vertical spring fastened to an overhead beam. The object is set into vertical

Alex_Xolod [135]

Answer:

109.32 N/m

Explanation:

Given that

Mass of the hung object, m = 8 kg

Period of oscillation of object, T = 1.7 s

Force constant, k = ?

Recall that the period of oscillation of a Simple Harmonic Motion is given as

T = 2π √(m/k), where

T = period of oscillation

m = mass of object and

k = force constant if the spring

Since we are looking for the force constant, if we make "k" the subject of the formula, we have

k = 4π²m / T², now we go ahead to substitute our given values from the question

k = (4 * π² * 8) / 1.7²

k = 315.91 / 2.89

k = 109.32 N/m

Therefore, the force constant of the spring is 109.32 N/m

8 0

2 years ago

Suppose a ball of putty moving horizontally with 1kg.m/s of momentum collides and sticks to an identical ball of puffy moving ve

WARRIOR [948]

Answer:

Vector sum of two vectors at right angles

p={p₁²+p₂²} =2 =1.41 kg•m/s

Explanation:

5 0

3 years ago

A cycle track is 500 metres long. Amy completes 10 laps. She travelled at an average speed of 12.5 metres per second. She puts o

yanalaym [24]

The fast lap is irrelevant to the question, because it didn't happen
until after the 9 laps that you're interested in.

To be perfectly technical about it, we don't actually have enough
information to answer the question. You told us her average speed
for 10 laps, but we don't know anything about how her speed may
have changed during the whole 10 laps. For all we know, maybe
she took a nap first, and then got up and drove 10 laps at the speed
of 125 metres per second. That would produce the average speed
of 12.5 metres per second and we would never know it Why not ?
That's only 280 miles per hour. Bikes can do that, can't they ?

IF we can assume that Amy maintained a totally steady pace through
the entire 10 laps, then we could say that her average for 9 laps was
also 12.5 metres per second.

5 0

3 years ago