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Nadya [2.5K]
2 years ago
11

A majorette in the Rose Bowl Parade tosses a baton into the air with an initial angular velocity of 2.5 rev/s. If the baton unde

rgoes a constant acceleration while airborne of 0.2 rev/s2 and its angular velocity is 0.8 rev/s when the majorette catches it, how many revolutions does it make in the air?
Physics
1 answer:
oksian1 [2.3K]2 years ago
4 0

Answer:

14 rev

Explanation:

w_{o} = initial angular velocity = 2.5 revs⁻¹

w = final angular velocity = 0.8 revs⁻¹

\alpha = Angular acceleration = - 0.2 revs⁻²

\theta = Angular displacement

Using the equation

w^{2} = w_{o}^{2} + 2 \alpha \theta\\0.8^{2} = 2.5^{2} + 2 (- 0.2) \theta\\ \theta = 14 rev

So the number of revolutions are 14

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pitot tube on an airplane flying at a standard sea level reads 1.07 x 105 N/m2. What is the velocity of the airplane?
Allushta [10]

Answer:

V_infinty=98.772 m/s

Explanation:

complete question is:

The following problem assume an inviscid, incompressible flow. Also, standard sea level density and pressure are 1.23kg/m3(0.002377slug/ft3) and 1.01imes105N/m2(2116lb/ft2), respectively. A Pitot tube on an airplane flying at standard sea level reads 1.07imes105N/m2. What is the velocity of the airplane?

<u>solution:</u>

<u>given:</u>

<em>p_o=1.07*10^5 N/m^2</em>

<em>ρ_infinity=1.23 kg/m^2</em>

<em>p_infinity=1.01*10^5 N/m^2</em>

p_o=p_infinity+(1/2)*(ρ_infinity)*V_infinty^2

V_infinty^2=9756.097

V_infinty=98.772 m/s

8 0
2 years ago
You decide to work at a heart rate of 150 instead of 120. What area of F.I.T.T. did you change?
Rina8888 [55]

Key concepts

Heart rate

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Cardiovascular system

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Your heart is continuously beating to keep blood circulating throughout your body. Its rate changes depending on your activity level; it is lower while you are asleep and at rest and higher while you exercise—to supply your muscles with enough freshly oxygenated blood to keep the functioning at a high level. Because your heart is also a muscle, exercise, in turn, helps keep it healthy. The American Heart Association recommends that a person does exercise that is vigorous enough to raise their heart rate to their target heart-rate zone—50 percent to 85 percent of their maximum heart rate, which is 220 beats per minute (bpm) minus their age for adults—for at least 30 minutes on most days, or about 150 minutes a week in total. So for a 20-year-old, the maximum heart rate would be 200 bpm, with a target heart-rate zone of 100 to 170 bpm. (For those 19 or younger, target zones can vary more than they do for adults.)

i think it will help you...if it help you ...please mark brainless

8 0
2 years ago
A turntable that is initially at rest is set in motion with a constant angular acceleration α. What is the magnitude of the angu
bekas [8.4K]

Explanation:

If the turntable starts from rest and is set in motion with a constant angular acceleration α. Let \omega is the angular velocity of the turntable. We know that the rate of change of angular velocity is called the angular acceleration of an object. Its formula is given by :

\alpha =\dfrac{\omega_f-\omega_i}{t}

\alpha =\dfrac{\omega-0}{t}

\alpha =\dfrac{\omega}{t}

t=\dfrac{\omega}{\alpha }............(1)

Using second equation of kinematics as :

\theta=\omega_i t+\dfrac{1}{2}\alpha t^2

\theta=\dfrac{1}{2}\alpha t^2

Using equation (1) in above equation

\theta=\dfrac{1}{2}\times \dfrac{\omega^2}{\alpha }

In one revolution, \theta=4\pi (in 2 revolutions)

4\pi =\dfrac{1}{2}\times \dfrac{\omega^2}{\alpha }

\omega=\sqrt{8\pi \alpha}

\omega=2\sqrt{2\pi \alpha}

Hence, this is the required solution.

6 0
2 years ago
Read 2 more answers
At what height h above the ground does the projectile have a speed of 0.5v?
maw [93]

Answer:

h=\dfrac{3v^2}{8g}

Explanation:

It is given that,

Speed of the projectile is 0.5 v. Let h is the height above the ground. Using the first equation of motion to find it.

v=u+at

v=u-gt

Initial speed of the projectile is v and final speed is 0.5 v.

0.5v=v-gt

t=\dfrac{v}{2g}

g is the acceleration due to gravity

Let h is the height above the ground. Using the second equation of motion as :

h=vt-\dfrac{1}{2}gt^2

h=v\dfrac{v}{2g}-\dfrac{1}{2}g(\dfrac{v}{2g})^2

h=\dfrac{3v^2}{8g}

So, the height of the projectile above the ground is \dfrac{3v^2}{8g}. Hence, this is the required solution.

6 0
1 year ago
Centripetal force Fc acts on a car going around a curve. If the speed of the car were twice as great, the magnitude of the centr
kondaur [170]

Answer:

We need 4 times more force to keep the car in circular motion if the velocity gets double.

Explanation:

Lets take the mass of the car = m

The radius of the arc = r

F=\frac{m\times v^2}{r}

Given that speed of the car gets double ,v' = 2 v

Then the force on the car = F'

F'=\frac{m\times v'^2}{r}  ( radius of the arc is constant)

F'=\frac{m\times (2v)^2}{r}

F'=4\times \frac{m\times v^2}{r}

We know that F=\frac{m\times v^2}{r}

Therefore F' = 4 F

So we can say that we need 4 times more force to keep the car in circular motion if the velocity gets double.

6 0
2 years ago
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