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3 years ago

HELP PLS 100 POINTS TAKING TEST RN

Physics

2 answers:

s2008m [1.1K]3 years ago

8 0

Answer:

I think he answer is C but I could be wrong

Explanation:

brainliest plz

guajiro [1.7K]3 years ago

3 0

Answer:

d mark brainlyest

Explanation:

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Describe at least TWO hazardous conditions that exist in space AND the technological features a spacecraft must have in order to

nexus9112 [7]

gamma radiation and heat flares from the sun, they use refelective gold sheets

3 0

3 years ago

Please help

WITCHER [35]

Gravity is the force that pulls you down.
(This is kind of a duh! question ... How do we know
which way is "down" ? We feel gravity, and we call
that the "down" direction.)

Magnetic force holds things to fridge doors.

Contact forces need to touch something in order to
exert their force.
Example: Gravity is NOT a contact force.

I don't know about "rubbing things away".
This might be a description of friction, but if so,
it's not a good one.

Buoyant force is what keeps floating things floating.

Air resistance slows things down when they move in air.

4 0

4 years ago

We can reasonably model a 90-W incandescent lightbulb as a sphere 7.0cm in diameter. Typically, only about 5% of the energy goes

Ronch [10]

Answer:

292.3254055 W/m²

469.26267 V/m

$1.56421\times 10^{-6}\ T$

Explanation:

P = Power of bulb = 90 W

d = Diameter of bulb = 7 cm

r = Radius = $\frac{d}{2}=\frac{7}{2}=3.5\ cm$

$\epsilon_0$ = Permittivity of free space = $8.85\times 10^{-12}\ F/m$

c = Speed of light = $3\times 10^8\ m/s$

The intensity is given by

$I=\frac{P}{A}\\\Rightarrow I=\frac{90}{4\pi 0.035^2}\\\Rightarrow I=5846.50811\ W/m^2$

5% of this energy goes to the visible light so the intensity is

$I=0.05\times 5846.50811\\\Rightarrow I=292.3254055\ W/m^2$

The visible light intensity at the surface of the bulb is 292.3254055 W/m²

Energy density of the wave is

$u=\frac{1}{2}\epsilon_0E^2$

Energy density is also given by

$\frac{I}{c}=\frac{1}{2}\epsilon_0E^2\\\Rightarrow E=\sqrt{\frac{2I}{c\epsilon_0}}\\\Rightarrow E=\sqrt{\frac{2\times 292.3254055}{3\times 10^8\times 8.85\times 10^{-12}}}\\\Rightarrow E=469.26267\ V/m$

The amplitude of the electric field at this surface is 469.26267 V/m

Amplitude of a magnetic field is given by

$B=\frac{E}{c}\\\Rightarrow B=\frac{469.26267}{3\times 10^8}\\\Rightarrow B=1.56421\times 10^{-6}\ T$

The amplitude of the magnetic field at this surface is $1.56421\times 10^{-6}\ T$

7 0

3 years ago

To practice Problem-Solving Strategy 8.1 for circular-motion problems. A cyclist competes in a one-lap race around a flat, circu

Anna007 [38]

Answer:

Explanation:

distance travelled

s = 2πR

= 2 X 3.14 X 140

= 880 m

final velocity = v

initial velocity = u

distance travelled = s

time = 60 s

s = ut + 1/2 at²

880 = .5 x a x 60²

a = .244 m/s²

final velocity v = at

= .244 x 60

= 14.66

centripetal acceleration at final moment

v² /R

14.66 X 14.66 / 140

= 1.53 m/s⁻²

1.53 m/s²

this is centripetal acceleration which acts towards the centre.

tangential acceleration calculated a _t = .244

redial acceleration ( centripetal ) = 1.53

Resultant acceleration

R²= 1.53² + .244 ²

R = 1.55 m/s²

total force = 1.55 x 76

= 118 N

5 0

3 years ago

Cold water will warm to room temperature faster in a: a) Black pot

Viktor [21]

Answer:

black pot

Explanation:

option a is correct

Cold water will warm to room temperature faster in a Black pot as we know that Black surfaces and good absorbers of heat in comparison to other surfaces. Moreover, Silver a good reflector of heat. It reflects most of heat incident on it, the cold water will take longer time to come the room temperature in Silver pot.

8 0

4 years ago