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3 years ago

Is anyone good at physics who can help me??

Physics

2 answers:

Elenna [48]3 years ago

8 0

Answer: 7

Explanation:

I might be wrong but let me know if it is or not.

Viefleur [7K]3 years ago

4 0

Answer:

1.07 m/s

Explanation:

This is a simple speed distance time question.

first, we need to determine the distance between -11 and 4.

(think of a number line).

We add 4 to 11 using absolute value (i.e taking away negatives), and we get 15 m, our distance. We are attempting to find speed, and we have our time.

Speed is distance/time.

Now we have our equation, we plug in our variables.

speed (aka velocity)= 15/14.

speed= 1.07142857143

If we round to 2 place values, our speed is 1.07 m/s.

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Which was NOT a feature of welfare reform

qaws [65]

HeLLo tHeRe!

Your answer should be public transportation vouchers

Hope this helps. Have a nice day.

8 0

4 years ago

(7) A 2500 lbm car moving at 25 mi/hr is accelerated at a constant rate of 15 ft/s2 up to a speed of 50 mi/hr. What is the force

balandron [24]

Answer:

The force is $F = 1164.6\ lbf$

The time is $\Delta t = 2.44 \ s$

Explanation:

From the question we are told that

The mass of the car is $m = 2500 \ lbm$

The initial velocity of the car is $u = 25 \ mi/hr$

The final velocity of the car is $v = 50 \ mi/hr$

The acceleration is $a = 15 ft/s^2 = \frac{15 * 3600^2}{ 5280} = 36818.2 \ mi/h^2$

Generally the acceleration is mathematically represented as

$a = \frac{v-u}{\Delta t}$

=> $36818.2 = \frac{50 - 25 }{ \Delta t}$

=> $t = 0.000679 \ hr$

converting to seconds

$\Delta t = 0.0000679 * 3600$

=> $\Delta t = 2.44 \ s$

Generally the force is mathematically represented as

$F = m * a$

=> $F = 2500 * 15$

=> $F = 37500 \ \frac{lbm * ft}{s^2}$

Now converting to foot-pound-second we have

$F = \frac{37500}{32.2}$

=> $F = 1164.6\ lbf$

7 0

3 years ago

Three people pull simultaneously on a stubborn donkey. Jack pulls directly ahead of the donkey with a force of 64.7 N64.7 N , Ji

WARRIOR [948]

Answer:

(a) Magnitude of force is 262.51 N

(b) Angle with East direction is $-14.75^{o}$

Explanation:

Force by Jack in vector form

$\overrightarrow F _1} = 64.7{\rm{ N}}\left( {\hat i} \right)$

Force by Jill in Vector form is given by

$\begin{array}{c}\\{\overrightarrow F _2} = 86.5{\rm{ N }}\cos {\rm{4}}{{\rm{5}}^{\rm{o}}}\left( {\hat i} \right) + 86.5{\rm{ N }}\sin {\rm{4}}{{\rm{5}}^{\rm{o}}}\left( {\widehat j} \right)\\\\ = 61.16{\rm{ N}}\left( {\hat i} \right) + 61.16{\rm{ N}}\left( {\widehat j} \right)\\\end{array}$

Force by Jane is

$\begin{array}{c}\\{\overrightarrow F _3} = 181{\rm{ N }}\cos {\rm{4}}{{\rm{5}}^{\rm{o}}}\left( {\hat i} \right) + 181{\rm{ N }}\sin {\rm{4}}{{\rm{5}}^{\rm{o}}}\left( { - \widehat j} \right)\\\\ = 128{\rm{ N}}\left( {\hat i} \right) + 128{\rm{ N}}\left( { - \widehat j} \right)\\\end{array}$

Net force is:

$\overrightarrow F = {\overrightarrow F _1} + {\overrightarrow F _2} + {\overrightarrow F _3}$

Hence

$\begin{array}{c}\\\overrightarrow F = 64.7{\rm{ N}}\left( {\hat i} \right) + 61.16{\rm{ N}}\left( {\hat i} \right) + 61.16{\rm{ N}}\left( {\widehat j} \right) + 128{\rm{ N}}\left( {\hat i} \right) + 128{\rm{ N}}\left( { - \widehat j} \right)\\\\ = 253.86{\rm{ N}}\left( {\hat i} \right) - 66.84{\rm{ N}}\left( {\widehat j} \right)\\\end{array}$

The net force will be given by

$F = \sqrt {{{\left( {{F_x}} \right)}^2} + {{\left( {{F_y}} \right)}^2}$

Since $F_{x}=253.86N$ and $F_{y}=-66.84N$

$\begin{array}{c}\\F = \sqrt {{{\left( {253.86{\rm{ N}}} \right)}^2} + {{\left( { - 66.84{\rm{ N}}} \right)}^2}} \\\\ = {\bf{262.51 N}}\\\end{array}$

The direction of net force is:

$\theta = {\tan ^{ - 1}}\left {\frac{{{F_y}}}{{{F_x}}}}$

Since $F_{x}=253.86N$ and $F_{y}=-66.84N$

$\begin{array}{c}\\\theta = {\tan ^{ - 1}}\left( {\frac{{ - 66.84{\rm{ N}}}}{{253.86{\rm{ N}}}}} \right)\\\\ = {\tan ^{ - 1}}\left( { - 0.2633} \right)\\\\ = {\bf{ - 14}}{\bf{.7}}{{\bf{5}}^{\bf{o}}}\\\end{array}$

The angle with East direction is $-14.75^{o}$

Net force exerted on the donkey is in the south-east direction. So, the angle of net force from the east direction is $-14.75^{o}$ and it is $14.75^{o}$ from the south.

5 0

3 years ago

One small speaker is placed 3m to the east of a second speaker, and a listener stands 4m directly south of one of the speakers.

alexandr402 [8]

Answer:

The value is $\lambda = 2 \ m$

Explanation:

From the question we are told that

The distance of the speaker from the second speaker to the east is $d = 3 \ m$

The distance of the speaker from the listener to the south is $a = 4 \ m$

Generally given that if the speaker move in any direction, their sound become louder , it then mean that the position of the listener of minimum sound (i.e a position of minima ) ,

Generally the path difference of the sound produce by both speaker at a position of minima is mathematically represented as

$y = \frac{\lambda}{2}$

Generally considering the orientation of the speakers and applying Pythagoras theorem we see that distance from the second speaker to the listener is mathematically represented as

$b = \sqrt{d^ 2 + a^2 }$

=> $b = \sqrt{3^ 2 + 4^2 }$

=> $b = 5$

Generally the path difference between the two speaker with respect to the listener is

$y = b - a$

=> $y = 5 - 4$

=> $y = 1$

$1 = \frac{\lambda}{2}$

=> $\lambda = 2 \ m$

4 0

3 years ago

Describe the benefits and risks associated with nuclear energy.

Ulleksa [173]

Producing nuclear energy is far more environmentally friendly than burning fossil fuels. That is the main benefit.

The main risk is radiation. If the nuclear waste is not properly disposed of, it can leak radiation into the environment. Fortunately, this is not an issue since there are ways to deal with it. There is also the risk of a disaster like the Chernobyl incident, however that was mostly due to faulty reactor construction. However, reactors today are built to avoid such issues.

8 0

3 years ago