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3 years ago

A coin mass 0.005 kg is dropped from a height of 3 m. How much mechanical energy does it have right before it hits the ground ?

1 answer:

6 0

Mechanical energy equals the sum of potential and kinetic energy. During the process, all PE converts into KE, assuming air resistance is neglected. So, the mechanical energy does not change and is equal to the initial potential energy.
ME
=mgh
=0.005 x 9.81 x 3
=0.147J

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when two resistors are wired in series with a 12 v battery, the current through the battery is 0.31 a. when they are wired in pa

liberstina [14]

Let R₁ and R₂ be the two Resistance

R₁ - Resistance of 1st resistor

R₂ - Resistance of 2nd resistor

V = Voltage = 12V

I = O.31A ( in series)

I = 1.6 A ( in parallel)

when two resistance connected in series

Rs = R₁ + R₂

V = IRs = 12 /0.31 V

R₁+R₂ = 38.700Ω (equation1.)

When two resistance connected in parallel

$R_{p} =\frac { R_{1} R_{2}}{R_{1} + R_{2} }$

V = I Rp

V= I (R₂ R₁ /R₁ +R₂)

R₁ R₂ = 290.25 Ω

As we know

(R₁ - R₂ ) ² = (R₁ + R₂ ) ² - 4R1R2

Using above values we get,

(R₁ - R₂ ) ² = (38.70) ² - 4x 290.25

(R₁ - R₂ ) ² = 336.69 Ω

R₁ - R₂ = 18.34 (equation 2 )

Using equation 1 and 2 we get

R₁+ R₂ = 38.70 52

R₁ - R₂ = 18.34

R₁ = 28.535 Ω

Using the value of R₁ in equation 1 we get

R₂ = 38·700 - 28.535

RR₂ = 10.125 Ω

R₁ = 28. 535 v and R₂ 10.125 Ω

To know more about resistance in series and parallel:

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7 0

1 year ago

A dentist’s drill starts from rest. After 1.46 sof constant angular acceleration, it turns at arate of 27000 rev/min.Find the dr

Black_prince [1.1K]

Answer:

616.3 rad/s²

Explanation:

Given that

t= 1.46 s

Initial angular velocity ,ωi = 0 rad/s

Final angular velocity ωf= 27000 rev/min

Angular speed in the rad/s given as

$\omega_f=\dfrac{2\pi N}{60}\ rad/s$

Now by putting the values

$\omega_f=\dfrac{2\times 27000}{60}\ rad/s$

ωf=900 rad/s

We know that (if acceleration is constant)

ωf=ωi + α t

α=Angular acceleration

900 = 0 + α x 1.46

$\alpha=\dfrac{900}{1.46}\ rad/s^2\\\alpha=616.43\ rad/s^2$

Therefore the acceleration will be 616.3 rad/s²

4 0

3 years ago

Given that the distance from the left end of the string to the first antinode is 27.5 cm , calculate the wavelength of the stand

ivolga24 [154]

Answer:

= 0.55 m

Explanation:

A standing wave is characterized by anti-nodes and nodes.

Antinodes are points on a standing wave at maximum amplitude, while nodes are points on the standing wave that are stationary and have zero amplitude.

The distance between two adjacent nodes or two adjacent anti-nodes is equivalent to half the wavelength.

Therefore, in this case the half wavelength is 27.5 cm.

Thus, wavelength = 27.5 × 2

= 55 cm

6 0

3 years ago

The Number above the elements symobls is the elements atomic number .

Anna11 [10]

Answer:

correct

Explanation:

the atomic number is located top left of the atomic symbol given

4 0

3 years ago

A straight 1.20 m long conductor has a 2.00 A current travelling toward the East. Earth's magnetic field in this location is 4.9

KATRIN_1 [288]

Answer:

Force's magnitude $=1.176\,10^{-4}\,N$

Direction: down (towards the center of the Earth)

Explanation:

Recall that the magnetic force on a conductor of length L carrying a current I in a magnetic field B is given by the equation: $F=I\,L\,B$ in the case the magnetic field B and the direction of the current are at 90 degrees from each other (which is our case). The direction of the force will be given by the "right hand rule" associated with the vector product that defines this force.

Since the current is moving East, and the magnetic field of the Earth goes from North to South, the resultant Force vector will be pointing towards the Earth (and perpendicular to the plane defined by the current's direction and the magnetic field B)

The magnitude of the force, is given by the formula above, and given that all quantities to be considered are is SI units, it will result in Newtons (N):

$F=I\,L\,B\\F=2\,*\,1.2\,*\,4.9\,10^{-5}\,N\\F=1.176\,10^{-4}\,N$

8 0

3 years ago