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3 years ago

Describe the principle of conversation of energy:

Physics

1 answer:

exis [7]3 years ago

7 0

Answer: Energy can neither be created nor destroyed, rather it is converted from one form to another

Explanation:

The principle of conversation of energy explains how energy is conserved in nature by being converted from one form to another such that no energy is created nor destroyed.

Practical examples include:

- electrical pressing iron that converts electrical energy to heat energy

- solar panels that converts solar energy to electrical energy

- Car batteries that converts chemical energy to light energy etc

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An electron in an unknown energy level of a hydrogen atom transitions to the n=2 level and emits a photon with wavelength 410 nm

lyudmila [28]

Answer:

The initial energy level = 6

Explanation:

Photon wavelength is proportional to energy. The wavelength of emitted photons is related to the energy levels of the atom as given by the Rydberg formula:

ₕ₁₂

(1/λ) = Rₕ [(1/n₂²) − (1/n₁²)]

where n₂ = final energy level = 2

n₁ = initial energy level = ?

Rₕ = Rydberg's constant = 1.097 × 10⁷ m⁻¹

λ = wavelength = 410 nm = 410 × 10⁻⁹ m

1/(410 × 10⁻⁹) = (1.097 × 10⁷) [(1/2²) − (1/n₁²)]

0.223 = [(1/4) − (1/n₁²)]

(1/n₁²) = 0.02778

n₁² = 1/0.02778 = 36

n₁ = 6.

7 0

3 years ago

A pulsar is a rapidly rotating neutron star that emits a radio beam the way a lighthouse emits a light beam. We receive a radio

DanielleElmas [232]

Answer:

$\alpha =-2.2669642\times^{-10}rad/s^2$

Explanation:

Angular acceleration is defined by $\alpha =\frac{\Delta \omega}{\Delta t}=\frac{\omega_f-\omega_i}{\Delta t}$

Angular velocity is related to the period by $\omega=\frac{2\pi}{T}$

Putting all together:

$\alpha =\frac{\frac{2\pi}{T_f}-\frac{2\pi}{T_i}}{\Delta t}=\frac{2\pi}{\Delta t}(\frac{1}{T_f}-\frac{1}{T_i})$

Taking our initial (i) point now and our final (f) point one year later, we would have:

$\Delta t=1\ year=(365)(24)(60)(60)s=31536000
s$

$T_i=0.0786s$

$T_f=0.0786s+7.03\times10^{-6}s$

So for our values we have:

$\alpha =\frac{2\pi}{\Delta t}(\frac{1}{T_f}-\frac{1}{T_i})=\frac{2\pi}{31536000s}(\frac{1}{0.0786s+7.03\times10^{-6}s}-\frac{1}{0.0786s})=-2.2669642\times^{-10}rad/s^2$

Where the minus sign indicates it is decelerating.

8 0

3 years ago

A 56 kg diver runs and dives from the edge of a cliff into the water which is located 4.0 m below. If she is moving at 8.0 m/s t

Reil [10]

Answer:

1) 2197.44 J

2) 0 J

3) 2197.44 J = Constant

4) 2197.44 J

5) Approximately 8.86 m/s

Explanation:

The given parameters are;

The mass of the diver, m = 56 kg

The height of the cliff, h = 4.0 m

The speed with which the diver is moving, vₓ = 8.0 m/s

The gravitational potential energy = Mass, m × Height of the cliff, h × Acceleration due to gravity, g

1) Her gravitational potential energy = 56 × 4.0 × 9.81 = 2197.44 J

2) The kinetic energy = 1/2·m·u²

Where;

u = Her initial velocity = 0 when she just leaves the cliff

Therefore;

Her kinetic energy when she just leaves the cliff = 1/2 × 56 × 0² = 0 J

3) The total mechanical energy = Kinetic energy + Potential energy

The total mechanical energy is constant

Her total mechanical energy relative to the water surface when she leaves the cliff = Her gravitational potential energy = 2197.44 J = Constant

4) Her total mechanical energy relative to the water surface just before she enters the water = 2197.44 J

5) The speed with which she enters the water, v, is given from, v² = u² + 2·g·h

Where;

u = The initial velocity at the top of the cliff before she jumps= 0 m/s

∴ v² = 0² + 2 × 9.81 × 4 = 78.48

v = √78.48 ≈ 8.86 m/s

The speed with which she enters the water, v ≈ 8.86 m/s

7 0

2 years ago

A hiker walks due East for a distance of 6 km

solniwko [45]

Resultant displacement between the base camp and the cave will be 7.211 km

Displacement is a vector quantity that refers to "how far out of place an object is"; it is the object's overall change in position.

Her resultant displacement can be calculated using Pythagoras theorem

$H^{2} = P^{2} + B^{2}$

= $4^{2} + 6^{2}$

= 52

H = $\sqrt{52}$ = 7.211 km

Resultant displacement between the base camp and the cave will be 7.211 km

To learn more about displacement here :

brainly.com/question/13271165

#SPJ1

3 0

1 year ago

For long-distance transmission of power, in order to reduce losses in the wires by driving a low current at high voltage, we sho

rewona [7]

ans d) change the type of conducting matey

6 0

2 years ago

Read 2 more answers