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3 years ago

HELP ME

Physics

1 answer:

Mazyrski [523]3 years ago

3 0

Answer:

I THINK IT'S D....

HOPE SO

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Collar P slides outward at a constant relative speed along rod AB, which rotates counterclockwise with a constant angular veloci

diamong [38]

Answer:

a= 23.65 ft/s²

Explanation:

given

r= 14.34m

ω=3.65rad/s

Ф=Ф₀ + ωt

t = Ф - Ф₀/ω

= (98-0)× $\frac{\pi}{180}$ /3.65

98°= 1.71042 rad

1.7104/3.65

t= 0.47 s

r₁(not given)

assuming r₁ =20 in

r₁ = r₀ + ut(uniform motion)

u = r₁ - r₀/t

r₀ = 14.34 in= 1.195 ft

r₁ = 20 in = 1.67 ft

= (1.667 - 1.195)/0.47

0.472/0.47

u= 1.00ft/s

acceleration at collar p

a=rω²

= 1.67 × 3.65²

a = 22.25ft/s²

acceleration of collar p related to the rod = 0

coriolis acceleration = 2ωu

= 2× 3.65×1 = 7.3 ft/s²

acceleration of collar p

= 22.5j + 0 + 7.3i

√(22.5² + 7.3²)

the magnitude of the acceleration of the collar P just as it reaches B in ft/s²

a= 23.65 ft/s²

4 0

3 years ago

What are some common forces that make it difficult for humans to

Papessa [141]

Answer:

Explanation:

Applying Forces, doing Work and developing Power. Applying Forces: Force is a push or a pull and many forces are acting on you all of the time. ... possible to stretch the rubber band with one hand using your thumb and finger at two different places but ... If you are smart, however, just exerting forces, shouldn't get you tired

3 0

3 years ago

A thermally isolated system consists of a hot piece of aluminum and a cold piece of copper. The aluminum and the copper are in t

Marrrta [24]

Answer:

the amount of heat that gets through both the wires will be same.

Explanation:

By the Fourier's law of conduction we have:

$\dot{Q}=k.A.\frac{dT}{dx}$

where:

$\dot{Q}$ = rate of heat transfer

k = thermal conductivity of the material

A = area of the material

dT = temperature difference across the length dx

According to the question, the system to be analysed is isolated from the surrounding.

Until the thermal equilibrium is established between aluminium and copper wires the amount of heat that gets through both the wires will be same.

But the rate of heat transfer through the aluminium will be greater as it has double the thermal conductivity of copper.

8 0

3 years ago

A pendulum consists of a 2.0 kg stone swinging on a4.0 m string of negligible mass. The stone has a speed of 8.0 m/swhen it pass

arlik [135]

Answer:

a) $v_{60^{o}} =4.98 m/s$

b) $\theta_{max}=79.34^{o}$

Explanation:

This problem can be solved by doing an energy analysis on the given situation. So the very first thing we can do in order to solve this is to draw a diagram of the situation. (see attached picture)

So, in an energy analysis, basically you will always have the same amount of energy in any position of the pendulum. (This is in ideal conditions) So in this case:

$K_{lowest}+U_{lowest}=K_{60^{o}}+U_{60^{0}}$

where K is the kinetic energy and U is the potential energy.

We know the potential energy at the lowest of its trajectory will be zero because it will have a relative height of zero. So the equation simplifies to:

$K_{lowest}=K_{60^{o}}+U_{60^{0}}$

So now, we can substitute the respective equations for kinetic and potential energy so we get:

$\frac{1}{2}mv_{lowest}^{2}=\frac{1}{2}mv_{60^{o}}^{2}+mgh_{60^{o}}$

we can divide both sides of the equation into the mass of the pendulum so we get:

$\frac{1}{2}v_{lowest}^{2}=\frac{1}{2}v_{60^{o}}^{2}+gh_{60^{o}}$

and we can multiply both sides of the equation by 2 to get:

$v_{lowest}^{2}=v_{60^{o}}^{2}+2gh_{60^{o}}$

so we can solve this for $v_{60^{o}}$ . So we get:

$v_{60^{o}}=\sqrt{v_{lowest}^{2}-2gh_{60^{0}}}$

so we just need to find the height of the stone when the pendulum is at a 60 degree angle from the vertical. We can do this with the cos function. First, we find the vertical distance from the axis of the pendulum to the height of the stone when the angle is 60°. We will call this distance y. So:

$cos \theta = \frac{y}{4m}$

so we solve for y to get:

$y = 4cos \theta$

so we substitute the angle to get:

y=4cos 60°

y=2 m

so now we can find the height of the stone when the angle is 60°

$h_{60^{o}}=4m-2m$

$h_{60^{o}}=2m$

So now we can substitute the data in the velocity equation we got before:

$v_{60^{o}}=\sqrt{v_{lowest}^{2}-2gh_{60^{0}}}$

$v_{60^{o}} = \sqrt{(8 m/s)^{2}-2(9.81 m/s^{2})(2m)}$

$v_{60^{o}}=4.98 m/s$

b) For part b, we can do an energy analysis again to figure out what the height of the stone is at its maximum height, so we get.

$K_{lowest}+U_{lowest}=K_{max}+U_{max}$

In this case, we know that $U_{lowest}$ will be zero and $K_{max}$ will be zero as well since at the maximum point, the velocity will be zero.

So this simplifies our equation.

$K_{lowest} =U_{max}$

And now we substitute for the respective kinetic energy and potential energy equations.

$\frac{1}{2}mv_{lowest}^{2}=mgh_{max}$

again, we can divide both sides of the equation into the mass, so we get:

$\frac{1}{2}v_{lowest}^{2}=gh_{max}$

and solve for the height:

$h_{max}=\frac{v_{lowest}^{2}}{2g}$

and substitute:

$h_{max}=\frac{(8m/s)^{2}}{2(9.81 m/s^{2})}$

to get:

$h_{max}=3.26m$

This way we can find the distance between the axis and the maximum height to determine the angle of the pendulum about the vertical.

y=4-3.26 = 0.74m

next, we can use the cos function to find the max angle with the vertical.

$cos \theta_{max}= \frac{0.74}{4}$

$\theta_{max}=cos^{-1}(\frac{0.74}{4})$

so we get:

$\theta_{max}=79.34^{o}$

5 0

3 years ago

The frequency of a microwave signal is 9.76 ghz. what is its wavelength? (c = 3.00 × 108 m/s)

dolphi86 [110]

The basic relationship between frequency of an electromagnetic wave and wavelength of the wave is
$c = \lambda f$
where $c=3 \cdot 10^8 m/s$ is the speed of light.

Manipulating the equation, we can rewrite it as
$\lambda = \frac{c}{f}$

The frequency of the wave in our problem is
$9.76 GHz = 9.76 \cdot 10^9 Hz$
so if we use the previous formula, we find the correspondant wavelength:
$\lambda = \frac{3 \cdot 10^8 m/s}{9.76 \cdot 10^9 Hz} =0.031 m$

8 0

3 years ago