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4 years ago

10

Calculate the change in temperature of 20 kg of water if 30 kg of aluminum is dropped in the water and the aluminum changes temp

erature by 20°C (Hint: use the principle of conservation of energy.) °C

1 answer:

vivado [14]4 years ago

6 0

<span>ΔE = 0

(m_alum) (c_alum) Δt - (m_water)(c_water) Δt' = 0

(30) (897) (20) - (20)(4186) Δt' = 0

Δt' = 6.42857 °C</span>

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In a local bar, a customer slides an empty beer mug down the counter for a refill. The height of the counter is 1.46 m. The mug

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Answer:

(a). The horizontal velocity is 1.46 m/s.

(b). The direction of the mug's velocity just before it hit the floor is 74.7° below the horizontal.

Explanation:

Given that,

Height of the counter = 1.46 m

Distance = 0.80 m

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$s_{y}=ut+\dfrac{1}{2}gt^2$

$s_{y}=\dfrac{1}{2}gt^2$

Put the value into the formula

$1.46=\dfrac{1}{2}\times9.8\times t^2$

$t^2=\dfrac{1.46\times 2}{9.8}$

$t=\sqrt{\dfrac{1.46\times2}{9.8}}$

$t=0.545\ sec$

Here, horizontal velocity is constant

(a). We need to calculate the velocity

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$v_{x}=\dfrac{d}{t}$

Put the value into the formula

$v_{x}=\dfrac{0.80}{0.545}$

$v_{x}=1.46\ m/s$

(b). We need to calculate the final velocity

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$v_{f}^2=u^2+2as$

Put the value into the formula

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$v_{f}=\sqrt{28.616}$

$v_{f}=5.34\ m/s$

The velocity is 5.34 m/s downward.

We need to calculate the direction

Using formula of direction

$\tan\theta=\dfrac{v_{y}}{v_{x}}$

$\theta=\tan^{-1}(\dfrac{5.34}{1.46})$

$\theta=74.7^{\circ}$

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4 years ago

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Answer:

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The distance is

x = v t

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v = (v_nort ¾ t + v_sud ¼ t) / t

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3 years ago

On the International Space Station an object with mass m = 280 g is attached to a massless string L = 0.97 m. The string can han

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Answer:

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v is the speed

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Here we have:

m = 280 g = 0.280 kg

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The maximum tension allowed is

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Answer:

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2 years ago