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3 years ago

If the thrower takes 0.90 s to complete one revolution, starting from rest, what will be the speed of the discus at release?

1 answer:

8 0

Ω₀ = the initial angular velocity (from rest)
t = 0.9 s, time for a revolution
θ = 2π rad, the angular distance traveled

Let
α = the angular acceleration
ω = the final angular velocity

The angular rotation obeys the equation
(1/2)*(α rad/s²)*(0.9 s)² = (2π rad)
α = 15.514 rad/s²

The final angular velocity is
ω = (15.514 rad/s²)*(0.9 s) = 13.963 rad/s

If the thrower's arm is r meters long, the tangential velocity of release will be
v = 13.963r m/s

Answer: 13.963 rad/s

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A reaction that releases heat is: endothermic exothermic none of the above

Bas_tet [7]

Answer:

Exothermic reaction

Explanation:

A reaction that releases heat is known as an exothermic reaction.
Reactions can be classified as either exothermic or endothermic depending on whether they release or absorb heat from the surrounding.
A reaction that absorbs or gains heat from the surrounding is known as endothermic reaction.
On the other hand, if a reaction releases heat to the surrounding is known as exothermic reaction.
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3 years ago

An initially uncharged 3.47-μF capacitor and a 6.43-kΩ resistor are connected in series to a 1.50-V battery that has negligible

harkovskaia [24]

Answer: a) io=233.28 A ( initial current); b) τ=R*C= 22.31 ms; c) 81.7 ms

Explanation: In order to explain this problem we have to use, the formule for the variation of the current in a RC circuit:

I(t)=io*Exp(-t/τ)

and also we consider that io=V/R=(1.5/6.43*10^3)

=233.28 A

then the time constant for the RC circuit is τ=R*C=6.43*10^3*3.47*10^-6

=22.31 ms

Finally the time to reduce the current to 2.57% of its initial value is obtained from:

I(t)=io*Exp(-t/τ) for I(t)/io=0.0257=Exp(-t/τ) then

ln(0.0257)*τ =-t

t=-ln(0.0257)*τ=81.68 ms

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3 years ago

Consider the following mass distribution where the x- and y-coordinates are given in meters: 5.0 kg at (0.0, 0.0) m, 2.9 kg at (

Sauron [17]

Answer:

x = -1.20 m

y = -1.12 m

Explanation:

as we know that four masses and their position is given as

5.0 kg (0, 0)

2.9 kg (0, 3.2)

4 kg (2.5, 0)

8.3 kg (x, y)

As we know that the formula of center of gravity is given as

$x_{cm} = \frac{m_1 x_1 + m_2x_2 + m_3x_3 + m_4x_4}{m_1 + m_2 + m_3 + m_4}$

$0 = \frac{5(0) + 2.9(0) + 4(2.5) + 8.3 x}{5 + 2.9 + 4 + 8.3}$

$10 + 8.3 x = 0$

$x = -1.20 m$

Similarly for y direction we have

$y_{cm} = \frac{m_1 y_1 + m_2y_2 + m_3y_3 + m_4y_4}{m_1 + m_2 + m_3 + m_4}$

$0 = \frac{5(0) + 2.9(3.2) + 4(0) + 8.3 y}{5 + 2.9 + 4 + 8.3}$

$9.28 + 8.3 x = 0$

$x = -1.12 m$

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3 years ago

Jane's brother Andrew leaves home for school at 8:00 am. He walks at 3.3 kph. At 8:20 am Jane discovers that Andrew has left his

Gre4nikov [31]

8;30
i think hope i helped

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3 years ago

which form of energy does a battery-powered flashlight receive as an input? chemical A) potential energy B) radiant energy C) so

geniusboy [140]

I believe that the best answer among the choices provided by the question is the second choice ,B) radiant energy


Hope my answer would be a great help for you. If you have more questions feel free to ask here at Brainly.

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4 years ago

Read 2 more answers