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2 years ago

I need HELP ASAP please!!!

Physics

1 answer:

Katen [24]2 years ago

5 0

Answer: A

Explanation:i took this one

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When a 20-V emf is placed across two resistors in series, a current of 2.0 A is present in each of the resistors. When the same

ehidna [41]

Answer:

7.24 ohm

Explanation:

Let R1 and R2 are resistance of two resistors.

Emf=E=20 V

Current,I=2 A

Current,I'=10 A

We have to find the magnitude of the greater of the two resistances.

In series

$R=R_1+R_2$

$V=IR$

By using the formula

$20=2(R_1+R_2)$

$R_1+R_2=\frac{20}{2}=10$ ...(1)

In parallel

$\frac{1}{R}=\frac{1}{R_1}+\frac{1}{R_2}$

$\frac{1}{R}=\frac{R_2+R_1}{R_1R_2}$

$R=\frac{R_1R_2}{R_1+R_2}$

$20=10(\frac{R_1R_2}{R_1+R_2}$

$2=\frac{R_1R_2}{10}$

$R_1R_2=20$

$R_2=\frac{20}{R_1}$

Substitute the value

$\frac{20}{R_1}+R_1=10$

$R^2_1+20=10R_1$

$R^2_1-10R_1+20=0$

$R_1=\frac{10\pm\sqrt{(-10)^2-4(20)}}{2}$

By using quadratic formula

$x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}$

$R_1=\frac{10\pm 2\sqrt 5}{2}$

$R_1=\frac{10+2\sqrt 5}{2}=5+\sqrt 5=7.24 ohm$

$R_1=\frac{10-2\sqrt 5}{2}=2.76 ohm$

Substitute the value

$R_2=\frac{20}{7.24}=2.76 ohm$

$R_2=\frac{20}{2.76}=7.24 ohm$

Hence, the magnitude of the greater of the two resistance=7.24 ohm

8 0

2 years ago

Read 2 more answers

a toy dart gun generates a dart with .140kg.m/s momentum and a velocity of 4m/s. what is the mass of the dart in grams?

sleet_krkn [62]

Answer: m = 0.035kg = 35g

Explanation: Momentum p=0.140kgm/s

Velocity v=4m/s

Mass m=?

Formula-

Momentum depends on the mass of the object in motion and its velocity.

The equation for momentum is

p = mv

m = p/v

m = 0.140/4

m = 0.035kg

m = 35g

Hence, in the toy dart gun mass of the dart is 0.035kg.

4 0

2 years ago

Studying neutrinos helped to explain how our Sun works but led to changes in theories of particle physics, how is this process c

julsineya [31]

Explanation:

Yes, evidently, the process is consistent with the scientific process because in scientific process falsification and modification are two very important traits. So this new concept have modified the existing theories.

Through the modification a theory is adjusted without undermining other discovering made through the theory's prediction.

There are many other evidences that prove this fact for example Einstien's Theory of relativity also changes the existing concepts.

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2 years ago

Why do you ask me that’s all me the moon seem like they’re walking on Spring tomorrow on earth we are from your tractor to the g

nataly862011 [7]

The moon is talking to thecat at night that’s why

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2 years ago

3. An astronaut travels to a far-away moon with a 1.5 m long pendulum. She finds it takes

Reika [66]

Have you tried to look this up on Quizlet. I just had a similar question on one on my quizzes & the whole test was on Quizlet

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2 years ago