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2 years ago

15

Concave mirror ______the rays of light

1 answer:

Step2247 [10]2 years ago

3 0

Answer: A concave mirror focuses rays of light

Explanation:

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How do scientific tests help determine the properties of substances

tino4ka555 [31]

It can help determine substances that appear similar but react differently under the same circumstances.

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3 years ago

Help????????????????????

Elan Coil [88]

A. Six electrons
B. six protons
C. they are composed of two up quarks and one down quark.

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3 years ago

What mass of steam at 100°C must be mixed with 119 g of ice at its melting point, in a thermally insulated container, to produce

N76 [4]

Answer: $M=27.92\ gm$

Explanation:

Given

mass of ice $m=119\ gm$

Final temperature of liquid $T_f=57^{\circ}C$

Specific heat of water $c=4186\ J/kg-K$

Latent heat of fusion $L=333\ kJ/kg$

Latent heat of vaporization $L_v=2256\ kJ/kg$

Suppose M is the mass of steam at $100^{\circ} C$

Heat required to melt ice and convert it to water at $57^{\circ}C$

$Q_1=mL+mc(T_f-0)$

Heat released by steam

$Q_2=ML_v+Mc(100-T_f)$

$Q_1$ and $Q_2$ must be equal as the heat gained by ice is equal to Heat released by steam

$Q_1=Q_2$

$\Rightarrow mL+mc(T_f-0)= ML_v+Mc(100-T_f)$

$\Rightarrow M=\dfrac{m[L+c\times T_f]}{L_v+c(100-T_f)}$

$\Rightarrow M=\dfrac{119[333\times 10^3+4186\times 57]}{2256\times 10^3+4186\times (100-57)}$

$\Rightarrow M=119\times 0.2346$

$M=27.92\ gm$

7 0

3 years ago

Dale and Alex push on opposite sides of a couch. Dale pushes to the left with a force of 250 N, while Alex pushes to the right w

bonufazy [111]

F=ma
a=F/m

F=+250N + (-130N)=120N LEFT
('m summing my forces because they are moving about the same axis, and the negative/positive accounts for the arbitrary directions I assign)
m=32kg

F=120N/32kg=3.75m/s^2 to the LEFT

3.75m/s^2 to the LEFT

3 0

3 years ago

Read 2 more answers

An argon ion laser puts out 5.0 W of continuous power at a wavelength of 532 nm. The diameter of the laser beam is 5.5 mm. If th

stepan [7]

Answer:

Number of photons travel through pin hole= $6.4*10^{17}$

Explanation:

First we will calculate the energy of single photon using below formula:

$E=\frac{h*c}{λ}$

Where :

h is plank's constant with value $6.626*10^{-34} J.s$

c is the speed of light whch is $3*10^{8}$

λ is the wave length = 532nm

$E=\frac{6.6268*10^{-34}* 3*10^{8}}{532nm}$

E= $3.73*10^{-19}$ J

Number of photons emitted per second:

$\frac{5J/s}{1 photon/3.73*10^{-19} }$

Number of photons emitted per second= $1.34*10^{19} photons/s$

$\frac{A-hole}{A-beam}$ = $\frac{\frac{pie*d-hole^2}{4}}{\frac{pie*d-beam^2}{4} }$

Where:

A-hole is area of hole

A-beam is area of beam

d-hole is diameter of hole

d-beam is diameter if beam

$\frac{A-hole}{A-beam}$ = $\frac{d-hole^2}{d-beam^2}$

$\frac{Ahole}{A-beam}$ = $\frac{1.22^2}{5.5^2}$

$\frac{A-hole}{A-beam}$ = $\frac{144}{3025}$

Number of photons travel through pin hole= $1.34*10^{19} *\frac{144}{3025}$

Number of photons travel through pin hole= $6.4*10^{17}$

7 0

3 years ago