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3 years ago

Estimate the circumference of a circle that has a diameter of 13 yards

Mathematics

1 answer:

igomit [66]3 years ago

8 0

Answer:

aproximately 41 yards

Step-by-step explanation:

the equation equals 40.8 yards, rounded up is 41

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HELP 20 POINTS!! COMPARE 4.1 -3 1/2

GrogVix [38]

The answer to your question is <

-3 1/2 is greater that -4.1

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3 years ago

Read 2 more answers

On an alien planet with no atmosphere, acceleration due to gravity is given by g = 12m/s^2. A cannonball is launched from the or

almond37 [142]

Answer:

a) $\vec r (t) = \left[(90\cdot \cos \theta)\cdot t \right]\cdot i + \left[(90\cdot \sin \theta)\cdot t -6\cdot t^{2} \right]\cdot j$ , b) $\theta = \frac{\pi}{4}$ , c) $y_{max} = 84.375\,m$ , $t = 3.75\,s$ .

Step-by-step explanation:

a) The function in terms of time and the inital angle measured from the horizontal is:

$\vec r (t) = [(v_{o}\cdot \cos \theta)\cdot t]\cdot i + \left[(v_{o}\cdot \sin \theta)\cdot t -\frac{1}{2}\cdot g \cdot t^{2} \right]\cdot j$

The particular expression for the cannonball is:

$\vec r (t) = \left[(90\cdot \cos \theta)\cdot t \right]\cdot i + \left[(90\cdot \sin \theta)\cdot t -6\cdot t^{2} \right]\cdot j$

b) The components of the position of the cannonball before hitting the ground is:

$x = (90\cdot \cos \theta)\cdot t$

$0 = 90\cdot \sin \theta - 6\cdot t$

After a quick substitution and some algebraic and trigonometric handling, the following expression is found:

$0 = 90\cdot \sin \theta - 6\cdot \left(\frac{x}{90\cdot \cos \theta} \right)$

$0 = 8100\cdot \sin \theta \cdot \cos \theta - 6\cdot x$

$0 = 4050\cdot \sin 2\theta - 6\cdot x$

$6\cdot x = 4050\cdot \sin 2\theta$

$x = 675\cdot \sin 2\theta$

The angle for a maximum horizontal distance is determined by deriving the function, equalizing the resulting formula to zero and finding the angle:

$\frac{dx}{d\theta} = 1350\cdot \cos 2\theta$

$1350\cdot \cos 2\theta = 0$

$\cos 2\theta = 0$

$2\theta = \frac{\pi}{2}$

$\theta = \frac{\pi}{4}$

Now, it is required to demonstrate that critical point leads to a maximum. The second derivative is:

$\frac{d^{2}x}{d\theta^{2}} = -2700\cdot \sin 2\theta$

$\frac{d^{2}x}{d\theta^{2}} = -2700$

Which demonstrates the existence of the maximum associated with the critical point found before.

c) The equation for the vertical component of position is:

$y = 45\cdot t - 6\cdot t^{2}$

The maximum height can be found by deriving the previous expression, which is equalized to zero and critical values are found afterwards:

$\frac{dy}{dt} = 45 - 12\cdot t$

$45-12\cdot t = 0$

$t = \frac{45}{12}$

$t = 3.75\,s$

Now, the second derivative is used to check if such solution leads to a maximum:

$\frac{d^{2}y}{dt^{2}} = -12$

Which demonstrates the assumption.

The maximum height reached by the cannonball is:

$y_{max} = 45\cdot (3.75\,s)-6\cdot (3.75\,s)^{2}$

$y_{max} = 84.375\,m$

7 0

3 years ago

A spinning giant star of initial radius R1 and angular speed ω1 suddenly collapses radially inward reaching a new radius R2 = 0.

tiny-mole [99]

Answer:

K1/K2=4

Step-by-step explanation:

The kinetic energy of a rotating sphere is given by:

$K=\frac{I*\omega^{2} }{2}$

The moment of inertia of a solid sphere is given by

$I=\frac{2MR^{2} }{5}$

The initial kinetic energy is therefore

$K_1=\frac{2MR^{2}*\omega^{2} }{10}$

$K_1=\frac{MR_1^{2}*\omega^{2} }{5}$

The final kinetic energy is given by

$K_2=\frac{MR_2^{2}*\omega^{2} }{5}$

Therefore the relation K1/K2 if R2 = 0.5R1

$\frac{K_1}{K_2} =\frac{5M(R_1)^{2}*\omega^{2} }{5*M(0.5R_1)^{2} \omega^{2}}$

The text says nothing about the final angular velocity just the collapse of the collapse of the radius

$\frac{K_1}{K_2} =\frac{1 }{(0.5)^{2} }=4$

3 0

3 years ago

Determine whether the binomial is a factor of f(x).<br><br> f(x) = x3 + 11x2 + 24x - 36; x - 4

attashe74 [19]

If it is, then $f(4)$ would be equal $0$ .

$f(4)=4^3+11\cdot4^2+24\cdot4-36\\
f(4)=64+11\cdot16+96-36\\
f(4)=124+176\\
f(4)=300\not =0 \Rightarrow \text{ it isn't}$

8 0

3 years ago

Which of the following graphs has a zero at (-5)?

guapka [62]

Graph B would be the correct answer

6 0

2 years ago

Estimate the circumference of a circle that has a diameter of 13 yards​

Estimate the circumference of a circle that has a diameter of 13 yards