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2 years ago

I need help quick!! Urgent!

Physics

1 answer:

faltersainse [42]2 years ago

6 0

Explanation: Because mirrors are lighter, and they are easier than lenses to make perfectly smooth.

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A passenger train travels 392 mi in the same time that it takes a freight train to travel 322 mi. If the passenger train travels

Yuri [45]

Answer:

Explanation:

Given

distance traveled by Passenger train is $d_1=392\ mi$

distance traveled by Freight train is $d_2=322\ mi$

Both take same time to travel

suppose speed of freight train is x mph

so speed of passenger train is 20+x mph

we know time $=\frac{distance}{speed}$

$t=\frac{392}{20+x}=\frac{322}{x}$

$392x=322x+322\times 20$

$70x=322\times 20$

$x=92\ mph$

speed of passenger train $x+20=112\ mph$

6 0

2 years ago

The copper wire and bulb is connected in a series with 220 V electric supply. Why only an electric bulb glows where as the coppe

Sveta_85 [38]

-- In a series circuit, the current ( I ) is the same at every point.

-- The power dissipated by any section of the circuit is I² x Resistance.

-- The wire has very low resistance, so I²R is very low dissipated power.

-- The filament in the bulb has most all of the resistance in the circuit,
so it dissipates virtually all the power of the circuit, and certainly much
more than the wires do.

7 0

3 years ago

A radar operates at a wavelength of 3 centimeters. what is the frequency of the these waves? the speed of light is 3 × 108 m/s .

aliya0001 [1]

We are given information:
λ $= wavelength = 3cm = 0.03m \\ 
c = speed of light = 3* 10^{8}m/s$

Formula that connects wavelength and frequency is:
$frequency= \frac{speed of light}{wavelength} \\ f= \frac{3* 10^{8}}{0.03} \\ f=1 * 10^{10} Hz = 10GHz$

4 0

3 years ago

Would you die if you take the car keys out of the ignition and throw them in the back seat while you coast down a mountain-side

Archy [21]

Answer:

bro what.

Explanation:

... is this an actual physics question?

5 0

2 years ago

Which is the correct product of the significant figures 3278 and 42?

Svetradugi [14.3K]

Answer:

$1.4\cdot 10^5$

Explanation:

In multiplications or divisions, the result must be written using a number of significant figures equal to the smallest number of significant figures contained in the original numbers.

For instance, in this case the two numbers are:

3278 --> 4 significant figures

42 --> 2 significant figures

So, the product must be written using 2 significant figures.

Calculating the product, we get:

$3278\cdot 42=137676$

Therefore, using 2 significant figures only, the result is

$1.4\cdot 10^5$

8 0

2 years ago