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3 years ago

A rock of mass m is twirled on a string in a horizontal plane. The work done by the tension in the string on the rock is:

Physics

1 answer:

Varvara68 [4.7K]3 years ago

7 0

Answer: c) 0

Explanation:

Work tension is zero because in any infinitesimal time interval, the tension force is directly perpendicular to the displacement.

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Find the equevalent unit for Ohm using the geren formula. 늘

Brut [27]

Answer:

V/A

Explanation:

Resistance equals voltage divided by current. You already know resistance's unit is the Ohm. Voltage's unit is the Volt and current's is ths Ampere. Now you can do something like this:

1Ω= $\frac{1V}{1A}$ ⇔

Ω=V/A

Hope this helped :)

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3 years ago

When your standing in a subway train and the train suddenly stops but your body continues to move forward what Newton law is it

Aleksandr-060686 [28]

Newton's first law. Inertia.

If it's moving, it tends to keep moving.

"Stopped" tends to stay put

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4 years ago

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Alex has a 100 cm ruler pivoted at the centre. She ties a balloon filled with carbon doxide 16 cm from the pivot The total weigh

Leona [35]

If people send links report them

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3 years ago

How much work would be needed to raise the payload from the surface of the moon (i.e., x = r) to the "end of the universe"?

meriva

Moon was rotation Earth or sun
it's own orbit . universe is not end

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4 years ago

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A hot air balloon is on the ground, 200 feet from an observer. The pilot decides to ascend at 100 ft/min. How fast is the angle

liq [111]

Answer:

0.0031792338 rad/s

Explanation:

$\theta$ = Angle of elevation

y = Height of balloon

Using trigonometry

$tan\theta=y\dfrac{y}{200}\\\Rightarrow y=200tan\theta$

Differentiating with respect to t we get

$\dfrac{dy}{dt}=\dfrac{d}{dt}200tan\theta\\\Rightarrow \dfrac{dy}{dt}=200sec^2\theta\dfrac{d\theta}{dt}\\\Rightarrow 100=200sec^2\theta\dfrac{d\theta}{dt}\\\Rightarrow \dfrac{d\theta}{dt}=\dfrac{100}{200sec^2\theta}\\\Rightarrow \dfrac{d\theta}{dt}=\dfrac{1}{2}cos^2\theta$

Now, with the base at 200 ft and height at 2500 ft

The hypotenuse is

$h=\sqrt{200^2+2500^2}\\\Rightarrow h=2507.98\ ft$

Now y = 2500 ft

$cos\theta=\dfrac{200}{h}\\\Rightarrow cos\theta=\dfrac{200}{2507.98}=0.07974$

$\dfrac{d\theta}{dt}=\dfrac{1}{2}\times 0.07974^2\\\Rightarrow \dfrac{d\theta}{dt}=0.0031792338\ rad/s$

The angle is changing at 0.0031792338 rad/s

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3 years ago