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2 years ago

A laser is used to make a CD or DVD by _____.

Physics

1 answer:

boyakko [2]2 years ago

7 0

Answer:

Explanation:

Inside your CD player, there is a miniature laser beam called a semiconductor diode laser and a small photoelectric cell an electronic light detector. The laser flashes up onto the shiny side of the CD, bouncing off the pattern of pits and lands on the disc.

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The __________ on the left side of an equation must be balanced with the atoms on the right side of the equation.

zhannawk [14.2K]

Your answer would be total number of atoms! This is because when you have these equations which require total number of atoms.

3 0

3 years ago

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A high-jumper clears the bar and has a downward velocity of - 5.00 m/s just before landing on an air mattress and bouncing up at

Jobisdone [24]

-- As she lands on the air mattress, her momentum is (m v)

Momentum = (60 kg) (5 m/s down) = 300 kg-m/s down

-- As she leaves it after the bounce,

Momentum = (60 kg) (1 m/s up) = 60 kg-m/s up

-- The impulse (change in momentum) is

Change = (60 kg-m/s up) - (300 kg-m/s down)

Magnitude of the change = 360 km-m/s

The direction of the change is up /\ .

8 0

3 years ago

A 0.150 kg stone rests on a frictionless, horizontal surface. A bullet of mass 9.50 g, traveling horizontally at 380 m/s, strike

Anvisha [2.4K]

Answer:

(a)Magnitude=28.81 m/s

Direction=33.3 degree below the horizontal

(b) No, it is not perfectly elastic collision

Explanation:

We are given that

Mass of stone, M=0.150 kg

Mass of bullet, m=9.50 g= $9.50\times 10^{3} kg$

Initial speed of bullet, u=380 m/s

Initial speed of stone, U=0

Final speed of bullet, v=250m/s

a. We have to find the magnitude and direction of the velocity of the stone after it is struck.

Using conservation of momentum

$mu+ MU=mv+ MV$

Substitute the values

$9.5\times 10^{-3}\times 380 i+0.150(0)=9.5\times 10^{-3} (250)j+0.150V$

$3.61i=2.375j+0.150V$

$3.61 i-2.375j=0.150V$

$V=\frac{1}{0.150}(3.61 i-2.375j)$

$V=24.07i-15.83j$

Magnitude of velocity of stone

= $\sqrt{(24.07)^2+(-15.83)^2}$

|V|=28.81 m/s

Hence, the magnitude and direction of the velocity of the stone after it is struck, |V|=28.81 m/s

Direction

$\theta=tan^{-1}(\frac{y}{x})$

= $tan^{-1}(\frac{-15.83}{24.07})$

$\theta=tan^{-1}(-0.657)$

=33.3 degree below the horizontal

(b)

Initial kinetic energy

$K_i=\frac{1}{2}mu^2+0=\frac{1}{2}(9.5\times 10^{-3})(380)^2$

$K_i=685.9 J$

Final kinetic energy

$K_f=\frac{1}{2}mv^2+\frac{1}{2}MV^2$

= $\frac{1}{2}(9.5\times 10^{-3})(250)^2+\frac{1}{2}(0.150)(28.81)^2$

$K_f=359.12 J$

Initial kinetic energy is not equal to final kinetic energy. Hence, the collision is not perfectly elastic collision.

5 0

3 years ago

What two major uses does this (H-R)diagram have for astronomers?

EastWind [94]

66666666666666666666666666666666666666666666666666666666666666666666666666666666666666

7 0

3 years ago

An iron bar has more mass than a plastic bar of the same volume. so the iron bar will have greater inertia.

Irina-Kira [14]

The response is False, both bars, iron bars and plastic bars have de same inertia, this characteristic does not depend on the type of material, the inertia depends on his transverse section, since we can estimate in the following formula

Area moment of inertia Ixx = BH3/12

Area moment of inertia Iyy= HB3/12

6 0

3 years ago

Read 2 more answers