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3 years ago

a model rocket is launched at an angle of 55 to the horizontal with a momentum of 20 kg-m/. If the vertical component of its vel

ocity is 40 m/s what is the mass of the rocket?

Physics

1 answer:

den301095 [7]3 years ago

4 0

$Given:\\ \alpha =55^\circ\\p=20kg\cdot \frac{m}{s} \\v_v=40 \frac{m}{s} \\\\Find:\\m=?\\\\Solution:\\\\p_v=mv_v\Rightarrow m= \frac{p_v}{v_v} \\\\ \frac{p_v}{p} =\cos \alpha \Rightarrow p_v=p\cos \alpha \\\\m= \frac{p\cos \alpha }{v_v} \\\\m= \frac{20kg\cdot \frac{m}{s} \cdot \cos 55^\circ }{40 \frac{m}{s} } \approx 0.287kg=287g$

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Umnica [9.8K]

Answer:

L = ¼ k g / m

Explanation:

This is an interesting exercise, in the first case the spring bounces under its own weight and in the second it oscillates under its own weight.

The first case angular velocity, spring mass system is

w₁² = k / m

The second case the angular velocity is

w₂² = L / g

They tell us

w₂ = ½ w₁

Let's replace and calculate

√ (L / g) = ½ √ (k / m)

L / g = ¼ k / m

L = ¼ k g / m

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3 years ago

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Answer:

The value is $T_t = 2.5659 \ s$

Explanation:

From the we are told that

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Generally from kinematic equation we have that

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$0^2 = 8^2 + 2 * - 9.8 * H$

=> $H = 3.27 \ m$

Here H is the height from the initial height to the maximum height

So the initial height is mathematically represented as

$s = h - H$

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Generally the time taken for the object to reach maximum height is mathematically evaluated using kinematic equation as follows

$v = u + (-g) t$

At maximum height v = 0 m/s

$0 = 8 - 9.8t$

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Generally the time taken for the object to move from the maximum height to the ground is mathematically using kinematic equation as follows

$h = ut_1 + \frac{1}{2} gt_1^2$

Here the initial velocity is 0 m/s given that its the velocity at maximum height

Also g is positive because we are moving in the direction of gravity

$15 = 0* t + 4.9 t^2$

=> $t_1 = 1.7496$

Generally the total time taken is mathematically represented as

$T_t = t + t_1$

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3 years ago

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Answer:

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Buoyant force acting on the body depends on the volume immersed, density of liquid and gravity.

As the density of liquid is less than the density of water, so the buoyant force acting on the body by the unknown liquid is less than water. So it is submerged less than 90% in this liquid.

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3 years ago

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raketka [301]

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The right answer is

all of the above

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4 years ago