Calculate the average speed between seconds 2 and 4 PLS HELP!?

A 1500 kg weather rocket accelerates upward at 10m/s2. It explodes 2.0 s after liftoff and breaks into two fragments, one twice

ladessa [460]

Answer:

Approximately $\rm 19.8\; m\cdot s^{-1}$ (downwards.)

Assumptions:

the rocket started from rest;
the gravitational acceleration is constantly $\rm -9.8\; m \cdot s^{-2}$ ;
there's no air resistance on the rocket and the two fragments.
Both fragments traveled without horizontal velocity.

Explanation:

The upward speed of the rocket increases by $\rm 10\; m \cdot s^{-1}$ . If the rocket started from rest, the vertical speed of the rocket should be equal to $\rm 20\; m \cdot s^{-1}$ .

The mass of the rocket (before it exploded) is 1500 kilograms. At 20 m/s, its momentum will be equal to $\rm 20 \times 1500 = 30,000\; kg \cdot m\cdot s^{-1}$ .

What's the initial upward velocity, $u$ , of the lighter fragment?

The upward velocity of the lighter fragment is equal to $v = 0$ once it reached its maximum height of $x = \rm 530\; m$ .

$v^2 - u^2 = 2g \cdot x$ .

$\begin{aligned}u &= \sqrt{v^2 - 2g\cdot x} \\ &= \sqrt{-2 (-9.8) \times 530}\\ &\approx \rm 101.922\; m \cdot s^{-1}\end{aligned}$ .

Mass of the two fragments:

Lighter fragments: $\displaystyle \frac{1}{1 + 2} \times 1500 =\rm 500\; kg$ .
Heavier fragment: $\displaystyle \frac{2}{1 + 2} \times 1500 =\rm 1000\; kg$ .

Initial momentum of the lighter fragment:

$m \cdot v = \rm 10192.2\; kg \cdot m \cdot s^{-1}$ .

If there's no air resistance, momentum shall conserve. The momentum of the lighter fragment, plus that of the heavier fragment, should be equal to that of the rocket before it exploded.

The initial momentum of the heavier fragment should thus be equal to the momentum of the two pieces, combined, minus the initial momentum of the lighter fragment.

$\rm 30000 - 10192.2 = 19807.8\;kg \cdot m \cdot s^{-1}$ .

Velocity of the heavier fragment:

$\displaystyle \rm \frac{19807.8\;kg \cdot m \cdot s^{-1}}{1000\; kg} \approx 19.8\; m \cdot s^{-1}$ .

5 0

4 years ago

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The diagram shows the electric field lines surrounding two positive point charges. If the charge on the right were replaced with

WINSTONCH [101]

Answer:

Explanation:

The wording on some of these choices is very strange; I'm not sure exactly what they are stating. First of all, A. is definitely a choice because if both the charges were opposite, they would be attracted to one another as opposed to be repelled away from one another, as they are when they are both positive. What happens is that the charges go OUT from the positive charge and INTO the negative; so as far as the field lines around both charges would change direction...no; only the direction of the field lines would change on the positive charge (which is the one on the left). In that space where D is filled in by the field lines going OUT of the positive charge and INTO the negative one, the lines there are naturally closer together, and that is the point where the charge is the greatest. So if that is what is meant by the field lines getting closer together, then yes, they do. As far as choice D. again the field lines on the negative charge don't change, only the ones on the positive charge change.

4 0

3 years ago

Two equal magnitude electric charges are separated by a distance d. The electric potential at the midpoint between these two cha

Ann [662]

Answer:

The charges under study are of the same sign

The calculation of the electric field for each charge separately, there is no relationship between the charges

Explanation:

Let's start by writing the equation for the electric field

E = k q / r²

where q is the charge under analysis and r the distance from this charge to a positive test charge.

When analyzing the statement the student has some problems.

* The charges under study are of the same sign, it does not matter if positive or negative.

* The calculation of the electric field for each charge separately, there is no relationship between the charges for the calculation of the electric field.

* What is added is the interaction of the electric field with the positive test charge, in this case each field has the opposite direction to the other, so the vector sum gives zero

8 0

3 years ago

Which of the following is described here? "Point your skis straight down the fall line with your skis parallel and about a foot

elena55 [62]

answer d. down hill schussing

Explanation:

I took the quiz

3 0

3 years ago

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jack and his family go to the movies first they eat lunch at 1:30 pm it takes 40 minutes to eat then the movie then they drive 2

BabaBlast [244]