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4 years ago

Describe what causes day and night

2 answers:

7 0

The earth spins around the sun. The side facing away is cooler and darker, and experiences night.

Nana76 [90]4 years ago

7 0

The earths rotating axis causes different parts of the earth to be facing away from the sun therefore causing sunlight in some areas of the earth and night time in other areas

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During normal beating, the heart creates a maximum 4.00-mV potential across 0.300 m of a person’s chest, creating a 1.00-Hz elec

erik [133]

Answer:

(a). The maximum electric field strength is 0.0133 V/m.

(b). The maximum magnetic field strength in the electromagnetic wave is $4.433\times10^{-11}\ T$

(c). The wavelength of the electromagnetic wave is $3\times10^{8}\ m$

Explanation:

Given that,

Maximum potential = 4.00 mV

Distance = 0.300\ m

Frequency = 1.00 Hz

(a). We need to calculate the maximum electric field strength

Using formula of the potential difference

$\Delta V=Ed$

$E=\dfrac{\Delta V}{d}$

$E=\dfrac{4.00\times10^{-3}}{0.300}$

$E=0.0133\ V/m$

(b). We need to calculate the maximum magnetic field strength in the electromagnetic wave

Using formula of the maximum magnetic field strength in the electromagnetic wave

$B=\dfrac{E}{c}$

Put the value into the formula

$B=\dfrac{0.0133}{3\times10^{8}}$

$B=4.433\times10^{-11}\ T$

(c). We need to calculate the wavelength of the electromagnetic wave

Using formula of wavelength

$c=f\lambda$

$\lambda=\dfrac{c}{f}$

Put the value into the formula

$\lambda=\dfrac{3\times10^{8}}{1.00}$

$\lambda=3\times10^{8}\ m$

Hence, (a). The maximum electric field strength is 0.0133 V/m.

(b). The maximum magnetic field strength in the electromagnetic wave is $4.433\times10^{-11}\ T$

(c). The wavelength of the electromagnetic wave is $3\times10^{8}\ m$

4 0

3 years ago

Plasmodium belong to which kingdom

musickatia [10]

Answer:

plasmodium belongs to kingdom protista

4 0

3 years ago

What's the speed of a sound wave through water at 25° Celsius? A. 1,000 m/s B. 1,500 m/s C. 750 m/s D. 1,250 m/s

yan [13]

What's the speed of a sound wave through water at 25° Celsius?
 A. 1,250 m/s B. 1,500 m/s C. 750 m/s D. 1,000 m/s

5 0

3 years ago

Calculate the KE of a 3.1 kg toy cart that moves at 4.8 m/s. Calculate the KE of the same cart at twice the speed.

lisov135 [29]

When v= 4.8 m/s:

E.K=mv²/2
=3,1(4.8)²/2
=35.712J

when v= 2(4.8):

E.K=mv²/2
=3.1(9.6)²/2
=142.848J

4 0

4 years ago

A mail carrier leaves the post ofﬁce and drives 2.00 km to the north. He then drives in a direction 60.0° south of east for 7.00

Oxana [17]

Answer:

12.97 km

Explanation:

In order to find the resultant displacement, we have to resolve each of the 3 displacements along the x and y direction.

Taking north as positive y direction and east as positive x-direction, we have:

- Displacement 1: 2.00 km to the north

$A_x = 0\\A_y = +2.00 km$

- Displacement 2: 60.0° south of east for 7.00 km

$B_x=(7.00)(cos (-45^{\circ}))=4.95 km\\B_y = (7.00)(sin (-45^{\circ}))=-4.95 km$

- Displacement 3: 9.50 km 35.0° north of east

$C_x=(9.50)(cos 35^{\circ})=7.78 km\\C_y=(9.50)(sin 35^{\circ})=5.45 km$

So the net displacement along the two directions is:

$R_x=A_x+B_x+C_x=0+4.95+7.78=12.73 km\\R_y=A_y+B_y+C_y=2.00+(-4.95)+5.45=2.50 km$

So, the distance between the initial and final position is equal to the magnitude of the net displacement:

$R=\sqrt{R_x^2+R_y^2}=\sqrt{12.73^2+2.50^2}=12.97 km$

7 0

3 years ago