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NeX [460]
2 years ago
7

Is this right?? plssss help me

Physics
1 answer:
Andreas93 [3]2 years ago
7 0

Answer:

it is

Explanation:

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to what height will a 250g soccer ball rise to if it is kicked directly upwards at 8 meters per second​
Nonamiya [84]

Answer:

3.2 m

Explanation:

we know

Hmax = V²/2g

= 8² / 2*10 = 3.2

6 0
3 years ago
Read 2 more answers
A train whistle is heard at 300 Hz as the train approaches town. The train cuts its speed in half as it nears the station, and t
spin [16.1K]

Answer:

The speed of the train before and after slowing down is 22.12 m/s and 11.06 m/s, respectively.

Explanation:

We can calculate the speed of the train using the Doppler equation:

f = f_{0}\frac{v + v_{o}}{v - v_{s}}        

Where:

f₀: is the emitted frequency

f: is the frequency heard by the observer  

v: is the speed of the sound = 343 m/s

v_{o}: is the speed of the observer = 0 (it is heard in the town)

v_{s}: is the speed of the source =?

The frequency of the train before slowing down is given by:

f_{b} = f_{0}\frac{v}{v - v_{s_{b}}}  (1)                  

Now, the frequency of the train after slowing down is:

f_{a} = f_{0}\frac{v}{v - v_{s_{a}}}   (2)  

Dividing equation (1) by (2) we have:

\frac{f_{b}}{f_{a}} = \frac{f_{0}\frac{v}{v - v_{s_{b}}}}{f_{0}\frac{v}{v - v_{s_{a}}}}

\frac{f_{b}}{f_{a}} = \frac{v - v_{s_{a}}}{v - v_{s_{b}}}   (3)  

Also, we know that the speed of the train when it is slowing down is half the initial speed so:

v_{s_{b}} = 2v_{s_{a}}     (4)

Now, by entering equation (4) into (3) we have:

\frac{f_{b}}{f_{a}} = \frac{v - v_{s_{a}}}{v - 2v_{s_{a}}}  

\frac{300 Hz}{290 Hz} = \frac{343 m/s - v_{s_{a}}}{343 m/s - 2v_{s_{a}}}

By solving the above equation for v_{s_{a}} we can find the speed of the train after slowing down:

v_{s_{a}} = 11.06 m/s

Finally, the speed of the train before slowing down is:

v_{s_{b}} = 11.06 m/s*2 = 22.12 m/s

Therefore, the speed of the train before and after slowing down is 22.12 m/s and 11.06 m/s, respectively.                        

I hope it helps you!                                                        

7 0
2 years ago
What is the pendulum length whose period is 2.0s ?
Mashutka [201]
Formula\ for\ period:\\\ T=2 \pi \sqrt{\frac{L}{g}}\\\ g-gravity=9,8 \frac{m}{s^2} ,\ L-pendulum \ length \\\\ \frac{T}{2 \pi } = \sqrt{ \frac{L}{g} }|square\\\\ \frac{T^2}{2 \pi } = \frac{L}{g} \\\\\ \frac{T^2}{2 \pi }*g=L\\\\ L= \frac{2^2}{2*3,14 }*9,8= \frac{39,2}{6,28} =6,24mT=2 \pi   \sqrt{\frac{L}{g}} \\
 \frac{T}{2 \pi } = \sqrt{ \frac{L}{g} }|square\\
 \frac{T^2}{2 \pi }  = \frac{L}{g} \\
 \frac{T^2}{2 \pi }*g=L\\
L= \frac{2^2}{2*3,14 }*9,8= \frac{39,2}{6,28} =6,24m

7 0
3 years ago
An airplane flies with a velocity of 750. kilometers
viktelen [127]

Answer:

650 km/hr

Explanation:

Draw a right triangle from (0.0) (Point A) down 30 degrees and to the right for a length of 750 (Point B).  Then draw a line from B up to the x axis to make a right angle (Point C).  Use the cosine function to find line AC, the vector portion of AB that lies of the x (East) axis.  Cosine(30)= Adjacent/Hypotenuse.

Cos(30) = AC/750

750*(cos(30)) = AC

AC = 649.5 km/hr

5 0
2 years ago
Read 2 more answers
1:
LenKa [72]

The answer of question 1 is:

C. The gravitational force becomes 16 times less.

The answer of question 2 is:

A. The gravitational force is 12 times larger.

The answer of question 3 is :

A. The new gravitational force is 9 times stronger than the old one.

The answer of question 4 is:

D. 8 times more.

6 0
3 years ago
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