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3 years ago

What percentage of the power of the battery is dissipated across the internal resistance and hence is not available to the bulb?

Physics

1 answer:

spin [16.1K]3 years ago

5 0

Lets us consider an example:

Suppose a 10 ohm bulb is connected across the terminals of a 10 V

battery having 2ohm internal resistance.

Then total reistance in series we know, R1 + R2

Thus, R net = 10+ 2 = 12 ohm

The, current across circuit = 10/12= 0.833 A

Now, Power is given by $P = i^{2} R \\ \\$

Thus, power dissipated across internal resistance, P = $0.83^{2} * 2 = 1.37 Watt$

And, total power dissipated = $0.83^{2} * 12 = 8.2 watt$

Thsu, percentage of pwer not avaible = 1.37/8.2 = 16.70%

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Use Hooke's Law and Newton's 2nd Law to derive a formula for the acceleration of an object of mass m on a frictionless surface w

kramer

Answer:

a = kL/m

Explanation:

Here we can use Hooke's Law to find out the force applied on the system. Hooke's Law states that when a spring is stretched by some force, the force applied is directly proportional to the displacement of spring. The formula is given as:

F = kL

Now, the Newton's Second Law of motion states that whenever an unbalanced force is applied to a body it produces an acceleration in the body, in its own direction. So, the force is given by the formula:

F = ma

Comparing both the forces, we get:

kL = ma

a = kL/m

4 0

3 years ago

Which sets of data show a wave with the shortest wavelength? A. Speed=100 million m/s and frequency = 50 million Hz. B. Speed=15

SashulF [63]

The answer is A. Speed=100 million m/s and frequency = 50 million Hz.

Let's calculate for each choice the wavelength using the equation:
v = f × λ ⇒ λ = v ÷ f

where:
v - the speed,
f - the frequency,
λ - the wavelength.

A:
v = 100 000 000 m/s
f = 50 000 000 Hz = 50 000 000 1/s (Since f = 1/T, so units are Hz = 1/s)
⇒ λ = 100 000 000 ÷ 50 000 000 = 2 m

B:
v = 150 000 000 m/s
f = 1 500 Hz = 1 500 1/s
⇒ λ = 150 000 000 m/s ÷ 1 500 = 100 000 m

B:
v = 300 000 000 m/s
f = 100 Hz = 100 1/s
⇒ λ = 300 000 000 m/s ÷ 100 = 3 000 000 m

According to these calculations, the shortest wavelength is needed for choice A.

3 0

3 years ago

A 500 kg block is attached to a horizontal spring that is at its equilibrium length, and whose force constant is 30 N/m. The blo

m_a_m_a [10]

Answer:

x = 0.396 m

Explanation:

The best way to solve this problem is to divide it into two parts: one for the clash of the putty with the block and another when the system (putty + block) compresses it is spring

Data the putty has a mass m1 and velocity vo1, the block has a mass m2 . t's start using the moment to find the system speed.

Let's form a system consisting of putty and block; For this system the forces during the crash are internal and the moment is preserved. Let's write the moment before the crash

p₀ = m1 v₀₁

Moment after shock

$p_{f}$ = (m1 + m2) $v_{f}$

p₀ = $p_{f}$

m1 v₀₁ = (m1 + m2) $v_{f}$

$v_{f}$ = v₀₁ m1 / (m1 + m2)

$v_{f}$ = 4.4 600 / (600 + 500)

$v_{f}$ = 2.4 m / s

With this speed the putty + block system compresses the spring, let's use energy conservation for this second part, write the mechanical energy before and after compressing the spring

Before compressing the spring

Em₀ = K = ½ (m1 + m2) $v_{f}$ ²

After compressing the spring

$E_{mf}$ = Ke = ½ k x²

As there is no rubbing the energy is conserved

Em₀ = $E_{mf}$

½ (m1 + m2) $v_{f}$ ² = = ½ k x²

x = $v_{f}$ √ (k / (m1 + m2))

x = 2.4 √ (11/3000)

x = 0.396 m

7 0

3 years ago

What type of season does Daytona Beach, FL most likely have?

Alexus [3.1K]

i think its very hot summers

4 0

3 years ago

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What should a free-body diagram look like for a skydiver who has opened his parachute and is now slowing down as he falls?

mote1985 [20]

The last choice. Two arrows and the arrow up is shorter than the arrow down. Since the guy is falling and he’s opened his chute, he’s slowing down but he’s still falling meaning the force of gravity is stronger than the air resistance.

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3 years ago

Read 2 more answers