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2 years ago

5) Sally has a mass of 50 kg. She ran with a velocity of 20 m/s.

Physics

1 answer:

Ket [755]2 years ago

7 0

Answer:

Explanation:

The kinetic energy of an object can be found by using the formula

$k = \frac{1}{2} m {v}^{2} \\$

m is the mass

v is the velocity

From the question we have

$k = \frac{1}{2} \times 50 \times {20}^{2} \\ = 25 \times 400 \\ = 10000$

We have the final answer as

Hope this helps you

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Three equal charges of magnitude 'e' are located at the vertices of an equilateral triangle of side 1m. Where should you place a

Naily [24]

Answer:

At centroid

Explanation:

In the given equilateral triangle ABC with side of 1 m. The three equal charges e,e,e are placed at the A,B and C.

And the fourth charge 2e is put at point O which is called centroid.

Now we can calculate the distance AD by applying pythagorean theorem as,

$AD^{2}=AB^{2}+BD^{2}$

Put the values and get.

$AD^{2}=1^{2}+(\frac{1}{2} )^{2}\\AD=\sqrt{\frac{3}{4} } \\AD=\frac{\sqrt{3}}{2}$

Now calculate AO as,

$AO=\frac{2}{3}\times \frac{\sqrt{3} }{2}\\AO=\frac{1}{\sqrt{3} }$

And the sides BO=CO=AO.

Now Force can be calculated as

$F_{1}=\frac{2ke^{2} }{\frac{1}{\sqrt{3} } ^{2} }\\F_{1}=6ke^{2}$

And similarly,

$F_{2}=F_{3}=6ke^{2}$

Now we can calculate resultant of $F_{2}andF_{3}$ in upward direction. as,

$F_{net}=\sqrt{F_{2}^{2}+F_{3}^{2}+2F_{2}F_{3}cos120 } \\F_{net}=\sqrt{F_{2}^{2}+F_{2}^{2}+2F_{2}F_{2}(-\frac{1}{2})}\\F_{net}=6ke^{2}$

Therefore the resultant force on centroid O.

$F=F_{1}-F_{net}\\F=6ke^{2}-6ke^{2}\\F=0$

Therefore the fourth charge 2e should be placed on centroid so that it experience zero force.

8 0

3 years ago

In 1656, the Burgmeister (mayor) of the town of Magdeburg, Germany, Otto Von Guericke, carried out a dramatic demonstration of t

sleet_krkn [62]

Answer:

Force required to pull the two hemisphere = 46622.72N

Explanation:

Complete question ( Note: 1 millibar=100 N/m2. One atmosphere is 1013 millibar = 1.013×105 N/m2 ]

The contact area between the hemispheres is (pi x 0.400^2) = 0.5024m^2.

Pressure difference = (940 - 12) = 928 millibars.

(928 x 100) = 92,800N/m^2.

(92800 x 0.5024) = 46622.72N. force required to part the hemispheres.

6 0

3 years ago

Read 2 more answers

speed of sound is 343 Ms at 20 degrees Celsius. The frequency heard from the sound is 256 Hz. what is the sounds wavelength?

Lina20 [59]

S= 343m/s
F=256Hz

WL= 343ms/256-1
WL=V/F

= 1.339844m

7 0

3 years ago

You are trying to overhear a juicy conversation, but from your distance of 23.0 m , it sounds like only an average whisper of 40

Len [333]

If its asking the distance for the 65 db then use a proportion, if otherwise pleas clarify. It sounds like a pretty juicy conversation.

4 0

3 years ago

Please answer the following question!

Semmy [17]

Answer:

Explanation:

the momentum will always be 0 when it is at rest because the object isnt moving!

Hope this helped!

6 0

2 years ago