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2 years ago

Help with these questions please , 15 PTS & brainliest

Physics

1 answer:

myrzilka [38]2 years ago

6 0

For these two questions, first you need to know that the voltage across each branch of a parallel circuit is the same.

So, for Q5, we can first find out the voltage across R₂ by V=IR.

Voltage across R₂ = 2.5 × 8 = 20V

Since R₂ and R₃ are in parallel circuit, their voltage should be the same. Thus, voltage across R₃ is 20V.

So, by V=IR,

current of R₃ = $\frac{20}{4}$ = 5A

Q6. voltage across R₁ = 2 × 4 = 8V

∴voltage across R₂ = 8V

current of R₂ = $\frac{8}{8}$ = 1A

<h3>Alternative method</h3>

From these two examples, you can find out that the current of each branch of the parallel circuit is inversely proportional to the resistance of the branch.

ie. for Q5,

$\frac{R2}{R3}$ = $\frac{I3}{I2}$

$\frac{8}{4}$ = $\frac{I3}{2.5}$

I₃ = 5A

Q6. $\frac{R1}{R2}$ = $\frac{I2}{I1}$

$\frac{4}{8}$ = $\frac{I2}{2}$

I₂ = 1A

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It is possible a tree could fall down, even if no one did anything to it. A. True B. False

hichkok12 [17]

Answer:

This is TRUE

Explanation:

The tree can fall down even though no one did anything to it...

A hard breeze can blow and it can fall down or something else can cause it to topple...

Not only humans can make trees topple over...

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8 0

3 years ago

A dielectric material such as paper is inserted between the plates of a capacitor as the capacitor holds a fixed charge on its p

Vikki [24]

Answer:

Introducing a dielectric into a capacitor decreases the electric field, which decreases the voltage, which increases the capacitance.

Explanation:

A dielectric (or dielectric material) is an electrical insulator that can be polarized by an applied electric field. When a dielectric material is placed in an electric field, electric charges do not flow through the material as they do in an electrical conductor but only slightly shift from their average equilibrium positions causing dielectric polarization

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3 years ago

Which example demonstrates constant speed with changing direction?

Darya [45]

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2 years ago

If at 10m above the ground an object has 50J of Kinetic Energy, with 50J of Potential Energy. How high can the object travel?

steposvetlana [31]

Hi there!

$\large\boxed{\text{B) 20 meters}}$

We know that:

$E_T = U + K$

U = Potential Energy (J)

K = Kinetic Energy (J)

E = Total Energy (J)

At 10m, the total amount of energy is equivalent to:

U + K = 50 + 50 = 100 J

To find the highest point the object can travel, K = 0 J and U is at a maximum of 100 J, so:

100J = mgh

We know at 10m U = 50J, so we can solve for mass. Let g = 10 m/s².

50J = 10(10)m

m = 1/2 kg

Now, solve for height given that E = 100 J:

100J = 1/2(10)h

100J = 5h

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3 0

2 years ago

A bungee jumper with mass 65.0 kg jumps from a high bridge. After reaching his lowest point, he oscillates up and down, hitting

ololo11 [35]

Explanation:

It is given that,

Mass of a bungee jumper is 65 kg

The time period of the oscillation is 38 s, hitting a low point eight more times.It means its time period is

$T=\dfrac{38}{8}\\\\T=4.75\ s$

After many oscillations, he finally comes to rest 25.0 m below the level of the bridge.

For an oscillating object, the time period is given by :

$T=2\pi \sqrt{\dfrac{m}{k}}$

k = spring stiffness constant

So,

$k=\dfrac{4\pi ^2m}{T^2}\\\\k=\dfrac{4\pi ^2\times 65}{(4.75)^2}\\\\k=113.43\ N/m$

When the cord is in air,

mg=kx

x = the extension in the cord

$x=\dfrac{mg}{k}\\\\x=\dfrac{65\times 9.8}{113.6}\\\\x=5.6\ m$

So, the unstretched length of the bungee cord is equal to 25 m - 5.6 m = 19.4 m

5 0

2 years ago