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3 years ago

Please help!! :)

Physics

1 answer:

Andrews [41]3 years ago

8 0

Answer:

Option D. 9.47 V

Explanation:

We'll begin by calculating the equivalent resistance of the circuit. This can be obtained as follow:

Resistor 1 (R₁) = 20 Ω

Resistor 2 (R₂) = 30 Ω

Resistor 3 (R₃) = 45 Ω

Equivalent Resistance (R) =?

R = R₁ + R₂ + R₃ (series connections)

R = 20 + 30 + 45

R = 95 Ω

Next, we shall determine the current in the circuit. This can be obtained as follow:

Voltage (V) = 45 V

Equivalent Resistance (R) = 95 Ω

Current (I) =?

V = IR

45 = I × 95

Divide both side by 95

I = 45 / 95

I = 0.4737 A

Finally, we shall determine, the voltage across R₁. This can be obtained as follow:

NOTE: Since the resistors are in series connection, the same current will pass through them.

Current (I) = 0.4737 A

Resistor 1 (R₁) = 20 Ω

Voltage 1 (V₁) =?

V₁ = IR₁

V₁ = 0.4737 × 20

V₁ = 9.47 V

Therefore, the voltage across R₁ is 9.47 V.

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2 years ago

What is the smallest value of n for which the wavelength of a Balmer series line is less than 400 nm

Natasha_Volkova [10]

Answer:

The smallest value is n= 2

Explanation:

The balmer equation is given below

1/λ = R(1/4 - 1/n₂²).

R= 1.0973731568508 × 10^7 m^-1

λ= 400*10^-9 m

(400*10^-9)= 1.0973731568508 × 10^7 (1/4-1/n²)

(400*10^-9)/1.0973731568508 × 10^7

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364.51 *10^-16= 1/4 - 1/n²

1/n²= 1/4 -364.51 *10^-16

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7 0

3 years ago

The velocity time graph of a car shown below a) Calculate the magnitude of displacement of the car in 40 seconds. b) During whic

Gekata [30.6K]

Answer:

a) 0 metres

b) From time 0 s to 10 s , the car was accelerated. Its velocity accelerated from 0m/s to 20 m/s

c) 20 m/s

Explanation:

a) Formula of displacement= velocity x time

time=40 s

velocity =0 m/s

∴ displacement= 0 x 40 = 0 m

Magnitude of displacement is 0 m

b) The increase in velocity shows that there has been acceleration.

c) The average velocity of the car is = $\frac{0+40}{2\\}$ {initial velocity + final velocity}

= $\frac{40}{2}$

=20

Therefore, the magnitude of the average velocity of the car is 20 m/s

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3 years ago

two vehicles have a head on collision. one vehicle has a mass of 3000 kg and moves at 25 m/s while the second vehicle has a mass

emmasim [6.3K]

Answer:

The speed of the combined vehicles is 6.82m/s

Explanation:

Using the law of conservation of momentum which stayed that the sum of momentum of bodies before collision is equal to their sum of momentum after collision. After collision, both object moves with the same velocity.

Momentum = mass×velocity

Before collision:

Momentum of vehicle or mass 3000kg moving with velocity 25m/s

= 3000×25

= 75000kgm/s

Pa = 75000kgm/s

Momentum of vehicle with mass 2500kg moving with velocity of -15m/s

= 2500×-15

= -37500kgm/s

After collision:

Momentum = (3000+2500)V

Where v is their common velocity

Momentum after collision = 5500V

Based on the law:

75000+(-37500) = 5500V

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37500 = 5500V

V = 37500/5500

V = 6.82m/s

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3 years ago

n a ballistics test, a potato gun shoots a 0.34 kg potato into a 5.0 kg catching cart. The cart recoils at 3.7 m/s after catchin

Gala2k [10]

The initial velocity of the potato is 54.41 m/s.

The given parameters:

Mass of the potato, m = 0.34 kg
Mass of the cart, m = 5.0 kg
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The initial velocity of the potato is calculated by applying the principle of conservation of energy as follows;

$m_1u_1 = m_2 u_2\\\\u_1 = \frac{m_2 u_2}{m_1} \\\\u_1 = \frac{5 \times 3.7}{0.34} \\\\u_1 = 54.41 \ m/s$

Thus, the initial velocity of the potato is 54.41 m/s.

Learn more about conservation of linear momentum here: brainly.com/question/7538238

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3 years ago