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3 years ago

12

The star nearest to our Sun is called Proxima Centauri. It has a surface temperature of approximately 3000 Kelvin and a luminosi

ty about 1/1000th of the Sun’s. Which type of star is Proxima Centauri, and what color is it?

2 answers:

Mamont248 [21]3 years ago

4 0

Answer:

Proxima Centauri is a main sequence star, and it is red.

Explanation:

rusak2 [61]3 years ago

3 0

Ummmm is there any options?

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The particles in a balloon push out on the sides of the balloon. What is the reaction force?

saul85 [17]

The balloon wall pushes the enosed air particles inwards.

7 0

2 years ago

A 40.0-μFcapacitor is connected across a 60.0 Hz generator. An inductor is then connected in parallel with the capacitor. What i

amm1812

Answer:

The value of the inductance is 175.9 mH.

Explanation:

Given that,

Capacitor $C= 40.0\ \muF$

Frequency = 60.0 Hz

The inductor and capacitor is connected in parallel, the voltage across each of these elements is the same.

We have,

$V_{L}=V_{C}$

Using ohm's law

$I_{rms}\times X_{L}=I_{rms}\times X_{C}$

$X_{L}=X_{C}$

$2\pi f L=\dfrac{1}{2\pi f C}$

$L=\dfrac{1}{4\pi^2\times f^2\times C}$

Put the value into the formula

$L=\dfrac{1}{4\times\pi^2\times60.0^2\times40\times10^{-6}}$

$L=0.1759\ H$

$L=175.9\times10^{-3}\ H$

$L=175.9\ mH$

Hence, The value of the inductance is 175.9 mH.

5 0

4 years ago

Divers in Acapulco dive from a cliff that is 65 m high. If the rocks

Alex777 [14]

Answer:

Cool question! First step is to find the time taken to fall

57

m

, then to find the horizontal velocity needed to cover

24

m

in that time. In this case the answer is

7.0

m

s

−

1

.

Explanation:

This is a less typical projectile motion question, but it's still projectile motion. This means the horizontal and vertical directions can be considered separately. We assume that the initial vertical velocity,

u

y

=

0

m

s

−

1

, and we are trying to find the required initial horizontal velocity,

u

x

.

To find the time taken to fall

57

m

:

s

=

u

t

+

1

2

a

t

2

Since

u

=

0

, we can rearrange this to:

t

=

√

2

s

a

=

√

2

⋅

57

9.8

=

3.41

s

The horizontal velocity will be constant (ignoring air resistance), so to cover

24

m

in

3.41

s

will be given by:

v

=

s

t

→

u

x

=

24

3.41

=

7.0

m

s

−

1

Answer link

5 0

2 years ago

A 50.0-kg wolf is running at 10.0 m/sec. What is the wolfs kinetic energy

Fiesta28 [93]

Kinetic energy = mass time squared speed divided by 2
W=mv^2/2 = 50*10*10/2 = 2500 J

4 0

3 years ago

A box is put on a scale that is adjusted to read zero when the box is empty. A stream of marbles is then poured into the box fro

nadya68 [22]

Answer:

$F_{net} = 49 N$

Explanation:

As we know that rate of marble that strike the target is given as

$R = 120 per s$

now we know that after t = 8 s total marbles that accumulated in the box is given as

$N = Rt$

$N = 120(8)$

$N = 960$

now total weight of the marbles is given as

$W = N(mg)$

$W = 960(4.5 \times 10^{-3})(9.81)$

$W = 42.37 N$

Now force due to impact of marble is given as

$F = \frac{dN}{dt}mv$

$v = \sqrt{2gh}$

$v = \sqrt{2(9.81)(7.80)} = 12.37 m/s$

now we have

$F = 120(4.5 \times 10^{-3})(12.37)$

$F = 6.68 N$

so total force on the box is given as

$F_{net} = W + F$

$F_{net} = 42.37 + 6.68$

$F_{net} = 49 N$

6 0

3 years ago