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3 years ago

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A rocket is launched straight with a velocity of 50 m/s. It slows down, reverses direction, and returns to earth . what is the r

ockets velocity at its highest point above the ground?
A. 8.0 m/s
B. 0 m/s
C.50 m/s
D. -6.3m/s
E. -8.0 m/s

1 answer:

sertanlavr [38]3 years ago

8 0

At the highest point, where it changes from going up to coming down, the velocity is zero. (B)

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0.49 N
On a spring scale that measures force, a reading shows the force of an object to be about half way between 0 N and 1 N. 0. 49 Newton is the most accurate measurement for the force. If we cluster the number values of 0 N to 1 N It would be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0 N. These numbers indicate the micro intervals of 0-1. It cannot be the other given because the other values are either higher or lower which exceeds the 0-1 scale. Observe.

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A rock is suspended from a string, and it accelerates downward. Which one of the following statements is correct? Group of answe

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Answer:

a. The magnitude of the tension in the string is greater than the magnitude of the weight of the rock.

Explanation:

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so correct answer is

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3 years ago

A force of 80 N is exerted on an object on a frictionless surface for a distance of 4 meters. If the object has a mass of 10 kg,

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3 years ago

Which of the following best describes a capacitor?

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Answer:

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Explanation:

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3 years ago

Read 2 more answers

A solid metal sphere of diameter D is spinning in a gravity-free region of space with an angular velocity of ω. The sphere is sl

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Explanation:

It is given that, a solid metal sphere of diameter D is spinning in a gravity-free region of space with an angular velocity of ω.The sphere is slowly heated until it reaches its melting temperature, at which point it flattens into a uniform disk of thickness D/2.

The angular momentum remains conserved in this case. The relation between the angular momentum and the angular velocity is given by :

$I_s\times \omega_s=I_d\times \omega_d$

Where

$I_s\ and\ I_d$ are moment of inertia of sphere and the disk respectively

Here, volume before = volume after

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$r=\dfrac{D}{\sqrt{3} }=0.577\ D$

Initial angular momentum,

$L_i=I_s\times \omega_s$

$L_i=\dfrac{2mr^2}{5}\times \omega_s$

$L_i=\dfrac{2m(D/2)^2}{5}\times \omega_s$

$L_i=\dfrac{2mD^2}{20}\times \omega_s$ ..........(1)

Final angular momentum,

$L_d=I_f\times \omega_d$

$L_d=\dfrac{2mr^2}{5}\times \omega_d$

$L_d=\dfrac{2m(0.577D)^2}{5}\times \omega_d$ ............(2)

From equation (1) and (2) :

$\dfrac{2mD^2}{20}\times \omega_s=\dfrac{2m(0.577D)^2}{5}\times \omega_d$

$\dfrac{\omega_d}{\omega_s}=0.75$

Hence, this is the required solution.

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3 years ago