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3 years ago

IF YOU ANSWER THESE 4 QUESTIONS! I WILL GIVE YOU BRAINEST!!! 17 POINTS!!!

Physics

1 answer:

melisa1 [442]3 years ago

4 0

Answer:

1.d

2.d

3.c

4.c

Okay, d & d, c & c. Iknow what you're thinking, I guessed. Nope! I just took a good look and chosed what I thought was the best answer

Explanation:

Have a great day! Byeeee

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Which of the following best explains energy transformations that would occur if the archer were to release the bow string in eac

Yakvenalex [24]

Answer:

a)the arrow will have a very little kinetic energy after the archer and its realesead the string in the picture of the right

Explanation: you are at my same school and I pass it correct also as shown in the image it should be like that

4 0

3 years ago

A system absorbs 186 kj of heat and the surroundings do 110 kj of work on the system. what is the change in internal energy of t

hichkok12 [17]

296kJ

add the two, there you go

7 0

3 years ago

A student leaving school travels 100 m East before he realizes he left his textbook in his locker. He heads back towards school,

andrew11 [14]

-- The overall distance he travels is (100m + 30m + 70m) = 200 meters.

-- His displacement when he arrives at his front door is

D = (100m East) + (30m West) + (70m East)

D = (100m + 70m)East + (30m)West

D = (170m East) + (30m West)

D = 140 meters East

It's interesting to notice that his displacement is 60 meters shorter than the distance he walked.

That's because there's a stretch of 30 meters somewhere in the middle that he actually covered three times.

Two of those times added to the distance his shoes covered (2x30m=60m), but they cancelled out of the displacement.

His front door is 140 meters East of school. He walked 60m farther than that, going back and forth over the 30m piece.

6 0

4 years ago

An uncharged series RC circuit is to be connected across a battery. For each of the following changes, determine whether the tim

slavikrds [6]

a) Increase

b) Unchanged

c) Increase

Explanation:

The charge on a capacitor charging in a RC circuit connected to a battery follows the exponential equation:

$Q(t)=Q_0 (1-e^{-\frac{t}{RC}})$

where

$Q_0 = CV$ is the final charge stored in the capacitor, where C is the capacitance and V is the voltage of the battery

t is the time

R is the resistance of the circuit

The capacitor reaches 90% of its final charge when

$Q(t)=0.90Q_0$

Substituting and re-arranging the equation, we find:

$0.90Q_0 = Q_0(1-e^{-\frac{t}{RC}})\\0.90=1-e^{-\frac{t}{RC}}\\e^{-\frac{t}{RC}}=0.10\\-\frac{t}{RC}=ln(0.10)\\t=-RCln(0.10)=2.30RC$

We see that if we double the RC constant, then $(RC)'=2(RC)$

So the time taken will double as well:

$t'=2.30(RC)'=2.30(2RC)=2(2.30RC)=2t$

So, the answer is "increase"

In this second part, the battery voltage is doubled.

According to the equation written in part a),

$Q_0 =CV$

this means also that the final charge stored on the capacitor will also double.

However, the equation that gives us the time needed for the capacitor to reach 90% of its full charge is

$t=2.30 RC$

We see that this equation does not depend at all on the voltage of the battery.

Therefore, if the battery voltage is doubled, the final charge on the capacitor will double as well, but the time needed for the capacitor to reach 90% of its charge will not change.

So the correct answer is

"unchanged"

In this case, a second resistor is added in series with the original resistor of the circuit.

We know that for two resistors in series, the total resistance of the circuit is given by the sum of the individual resistances:

$R=R_1+R_2$

Since each resistance is a positive value, this means that as we add new resistors, the total resistance of the circuit increases.

Therefore in this problem, if we add a resistor in series to the original circuit, this means that the total resistance of the circuit will increase.

The time taken for the capacitor to reach 90% of its final charge is still

$t=2.30 RC$

As we can see, this time is directly proportional to the resistance of the circuit, R: therefore, if we add a resistor in series, the resistance of the circuit will increase, and therefore this time will increase as well.

So the correct answer is

"increase"

8 0

3 years ago

FOR EACH GROUP OF TERMS, WRITE A SENTENCE THAT SHOWSHOW THE TERMS ARE RELATED:

skad [1K]

1. A body is in motion when it changes its position at a certain time/duration.
2. Speed is related to how fast a body is moving.
3. Speed means that a body is moving and covering distance at a certain time.
4. Speed is the distance traveled by an object where as, velocity is distance traveled by an object per unit time in a particular direction. 
5. Velocity is the rate of change of distance or direction of a body with respect to time.

5 0

3 years ago