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kolbaska11 [484]

3 years ago

7

Consider three identical electric bulbs of power P. Two of bulbs are connected in series and the third one is connected in paral

lel to the first two. The total power dissipated in this circuit is: a. 2P/3 b. 3Pc. 2Pd. 3P/2e. P

1 answer:

Tamiku [17]3 years ago

6 0

Answer: 3P/2

Explanation: Let the resistance of the bulbs be R.

now lets consider a Voltage V is supplied to the parallel circuit such that

$P=VI=V^2/R$

V=IR

both single bulb( bulb 3) and the two bulbs ( bulb 1 and bulb 2) are provided the same Voltage

( as the voltage remains same in parallel circuit)

we can calculate the Current across both circuits

At Bulb 3

Current 1=V/R

Power1=Voltage * Current1

Power1=V*V/R

Power1=P

At Bulb 1 and Bulb 2

Total Resistance= R+R=2R

$Current2=\frac{V}{2R}$

Power2=Voltage * Current2

$Power2=V*\frac{V}{2R} \\Power2=\frac{V^2}{2R} \\Power2=P/2$

$TotalPower=Power1+Power2\\TotalPower=P+P/2\\TotalPower=\frac{3P}{2}$

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Two boxes (24 kg and 62 kg) are being pushed across a horizontal frictionless surface, as the drawing shows. The 36-N pushing fo

defon

Answer:

$F = 26.04 N$

Explanation:

As we know that system of two boxes are moving on frictionless surface

So here if two boxes are considered as a system

then we have

$F = (m_1 + m_2) a$

$m_1 = 24 kg$

$m_2 = 62 kg$

$F = 36 N$

$36 = (24 + 62) a$

$a = 0.42 m/s^2$

Now since we know that both the boxes are moving together so force applied by first box on other box is given as

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$F = (62 \times 0.42)$

$F = 26.04 N$

6 0

3 years ago

A railroad train is traveling at a speed of 26.0 m/s in still air. The frequency of the note emitted by the locomotive whistle i

olga55 [171]

Answer: 0.757m; 0.881m; 432.70Hz; 371.89Hz

Explanation:

Give the following :

Velocity of train (Vt) = 26m/s

Frequency of sound (Fs) = 420Hz

Speed of sound (Vs) = 344m/s

1) wavelength = (Vs - Vt) / Fs

Wavelength = (344 - 26) / 420 = 318/420 = 0.757m

11) Wavelength = (Vs + Vt) / Fs

Wavelength = (344 + 26) / 420 = 370/420 = 0.881m

111) According to the doppler effect :

Fl = [(V + Vl) / (V + Vs)] * fs

Fl = frequency of listener ; fs = frequency of sound source ; V = speed of sound ; Vl = Velocity of listener ; Vs = speed of sound source

Vs = - ve (train moving towards listener)

Fl = [(V + Vl) / (V + Vs)] * fs

Fl = [(344 + 0) / (344 - 26)] * 400

Fl = (344 / 318) * 400 = 432.70Hz

1V) Vs = + ve (train moving away listener)

Fl = [(V + Vl) / (V + Vs)] * fs

Fl = [(344 + 0) / (344 + 26)] * 400

Fl = (344 / 370) * 400 = 371.89Hz

6 0

3 years ago

because lighting heats up the surrounding air slowly, it realationship to thunder is currently unknown true or false

NeTakaya

Answer:

False

Explanation:

8 0

3 years ago

If ball C is 3 times the volume of ball D and ball D has 1/3 the mass of ball C, which has the greater density?

Alex Ar [27]

Answer:

They have same density

Explanation:

The density of an object is defined as

$d=\frac{m}{V}$

where

m is the mass of the object

V is its volume

Let's call $m_c$ and $V_c$ the mass and the volume of ball C, respectively. Therefore, the density of ball C is:

$d_c = \frac{m_c}{V_c}$

We know that the volume of ball C is 3 times the volume of ball D, so

$V_c = 3 V_d \rightarrow V_d = \frac{V_c}{3}$

And we also know that ball D has 1/3 the mass of ball C:

$m_d = \frac{m_c}{3}$

So, the density of ball D is:

$v_d = \frac{m_d}{V_d}=\frac{m_c/3}{V_d/3}=\frac{m_c}{V_c}=d_c$

Therefore, the two balls have same density.

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3 years ago

Energy of fossil fuel is also derived from solar energy why

zzz [600]

Explanation:

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8 0

2 years ago