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3 years ago

What is the density of a roll of pennies containing 50 pennies?

Physics

1 answer:

ololo11 [35]3 years ago

4 0

Answer:

Density is defined as:

Density = Mass/Volume

Now, density is an intensive property, this means that if you have 10 grams of a given material or 1000 grams of the same material, in both cases you will find the same density.

Then a roll of 50 pennies has the same density that a single penny.

The measures of a single penny are:

Mass = 2.5 g

Thickness = 1.52 mm

Radius = 9.525 mm

The coin is a cylinder, and the volume of a cylinder is:

V = pi*r^2*h

where:

pi = 3.14

r = radius = 9.525mm

h = thikness = 1.52mm

The volume is:

V = 3.14*(9.525mm)^2*1.52mm = 433.015 mm^3

The density will be:

D = 2.5g/433.015mm^3 = 0.00577 g/mm^3

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A particle of mass 4.5 × 10-8 kg and charge +5.4 μC is traveling due east. It enters perpendicularly a magnetic field whose magn

egoroff_w [7]

Answer:

0.00970 s

Explanation:

The centripetal force that causes the charge to move in a circular motion = The force exerted on the charge due to magnetic field

Force due to magnetic field = qvB sin θ

q = charge on the particle = 5.4 μC

v = velocity of the charge

B = magnetic field strength = 2.7 T

θ = angle between the velocity of the charge and the magnetic field = 90°, sin 90° = 1

F = qvB

Centripetal force responsible for circular motion = mv²/r = mvw

where w = angular velocity.

The centripetal force that causes the charge to move in a circular motion = The force exerted on the charge due to magnetic field

mvw = qvB

mw = qB

w = (qB/m) = (5.4 × 10⁻⁶ × 2.7)/(4.5 × 10⁻⁸)

w = 3.24 × 10² rad/s

w = 324 rad/s

w = (angular displacement)/time

Time = (angular displacement)/w

Angular displacement = π rads (half of a circle; 2π/2)

Time = (π/324) = 0.00970 s

Hope this Helps!!!

4 0

3 years ago

A laser of wavelength 720 nm illuminates a double slit where the separation between the slits is 0.22 mm. Fringes are seen on a

kumpel [21]

Answer:

The appropriate solution is "2.78 mm".

Explanation:

Given:

$\lambda = 720 \ nm$

or,

$= 720\times 10^{-9} \ m$

$D=0.85 \ m$

$d = 0.22 \ mm$

or,

$=0.22 \times 10^{-3} \ m$

As we know,

Fringe width is:

⇒ $\beta=\frac{\lambda D}{d}$

hence,

Separation between second and third bright fringes will be:

⇒ $\theta=\beta=\frac{\lambda D}{d}$

$=\frac{720\times 10^{-9}\times 0.85}{0.22\times 10^{-3}}$

$=2.78\times 10^{-3} \ m$

or,

$=2.78 \ mm$

8 0

2 years ago

is the following sentence true or false? the faster the particles of a substance are moving, the more energy they have.

svetlana [45]

I think true. I'm pretty sure, but check w/ others too.

8 0

3 years ago

Read 2 more answers

Assuming 84.0% efficiency for the conversion of electrical power by the motor, what current must the 13.0-V batteries of a 716 k

tino4ka555 [31]

Answer:

$\mathbf{ current(I) =1766.67 \ A}$

Explanation:

Given that:

The air resistance and friction = 700 N

The gravity caused force = 716 × 9.8 = 7016.8

Total force = (7016.8 + 700) N

Total force = 7716.8 N

∴

$13 \times current(I) \times 0.84 = \dfrac{7716.8 \times 300}{2 \times 60}$

$current(I) \times 10.92= 19292$

$current(I) = \dfrac{19292}{10.92}$

$\mathbf{ current(I) =1766.67 \ A}$

8 0

2 years ago

Pls help ASAP this questions are science questions ( biology chemistry physics)

Vilka [71]

Answer:

It would be A.

Explanation:

The scale goes from 0 to 14, With 0 being acidic and 14 being basic.

So if 7 is neutral, then anything less than 7 is moving more towards being more acidic. Anything higher than 7 is moving towards being more basic.

4 0

3 years ago

Read 2 more answers