Cavity wall insulation costs £240 but will save you £32 each year. What is the payback time for cavity

What is the difference between a light wave and an infrared wave?

Dmitriy789 [7]

Answer:Infrared light has a wavelength that is longer than that of standard red light, and although considered part of the red color spectrum, infrared wavelengths are still much shorter

6 0

3 years ago

Read 2 more answers

Please help me with this question

vovangra [49]

Answer:

1. 12 V

2a. R₁ = 4 Ω

2b. V₁ = 4 V

3a. A = 1.5 A

3b. R₂ = 4 Ω

4. Diagram is not complete

Explanation:

1. Determination of V

Current (I) = 2 A

Resistor (R) = 6 Ω

Voltage (V) =?

V = IR

V = 2 × 6

V = 12 V

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

Voltage (V) = 12 V

Current (I) = 1 A

Equivalent resistance (R) =?

V = IR

12 = 1 × R

R = 12 Ω

a. Determination of R₁

Equivalent resistance (R) = 12 Ω

Resistor 2 (R₂) = 8 Ω

Resistor 1 (R₁) =?

R = R₁ + R₂ (series arrangement)

12 = R₁ + 8

Collect like terms

12 – 8 =

4 = R₁

R₁ = 4 Ω

b. Determination of V₁

Current (I) = 1 A

Resistor 1 (R₁) = 4 Ω

Voltage 1 (V₁) =?

V₁ = IR₁

V₁ = 1 × 4

V₁ = 4 V

3a. Determination of the current.

Since the connections are in series arrangement, the same current will flow through each resistor. Thus, the ammeter reading can be obtained as follow:

Resistor 1 (R₁) = 4 Ω

Voltage 1 (V₁) = 6 V

Current (I) =?

V₁ = IR₁

6 = 4 × I

Divide both side by 4

I = 6 / 4

I = 1.5 A

Thus, the ammeter (A) reading is 1.5 A

b. Determination of R₂

We'll begin by calculating the voltage cross R₂. This can be obtained as follow:

Total voltage (V) = 12 V

Voltage 1 (V₁) = 6 V

Voltage 2 (V₂) =?

V = V₁ + V₂ (series arrangement)

12 = 6 + V₂

Collect like terms

12 – 6 = V₂

6 = V₂

V₂ = 6 V

Finally, we shall determine R₂. This can be obtained as follow:

Voltage 2 (V₂) = 6 V

Current (I) = 1.5 A

Resistor 2 (R₂) =?

V₂ = IR₂

6 = 1.5 × R₂

Divide both side by 1.5

R₂ = 6 / 1.5

R₂ = 4 Ω

4. The diagram is not complete

7 0

3 years ago

You can keep a 1kg apple from falling to the ground by placing it on a table. What reaction force is resisting the force of the

Gnom [1K]

The equilibrium condition allows finding the correct answer for the force that is resisting the weight of the apple is:

3. Normal force

Newton's second law gives the relationship between <em>force, mass</em> and acceleration of bodies, in the special case that the acceleration is is called the equilibrium condition.

∑ F = 0

Where F is the external force.

The free body diagram is a diagram of the forces on bodies without the details of the shape of the body, in the attached we can see a scheme of the forces.

Let's write the equilibrium condition for the apple

N - W = 0

N = W

.

We can see that the only forces acting on the apple are its weights and reaction from the table called Normal.

Let's analyze the different answers:

1. False. The apple is not moving therefore the resistance is zero

2. False. The apple is not moving so friction it with the table is

3. True. The free-body diagram shows that the normal and the weight are equal

4. False. There is nothing to pull the apple so there is no tension

5. False. Gravity is the weight of the apple that is applied to the table, not from the table to the apple.

In conclusion using the equilibrium condition we can find the correct result for the force that is resisting the weight of the apple is:

3. Normal force

Learn more here: brainly.com/question/2872207

8 0

3 years ago

In the diagram, R1 = 40.0 ,

Nostrana [21]

Answer:

51 Ω.

Explanation:

We'll begin by calculating the equivalent resistance of R₁ and R₃. This can be obtained as follow:

Resistor 1 (R₁) = 40 Ω

Resistor 3 (R₃) = 70.8 Ω

Equivalent Resistance of R₁ and R₃ (R₁ₙ₃) =?

Since the two resistors are in parallel connection, their equivalent can be obtained as follow:

R₁ₙ₃ = R₁ × R₃ / R₁ + R₃

R₁ₙ₃ = 40 × 70.8 / 40 + 70.8

R₁ₙ₃ = 2832 / 110.8

R₁ₙ₃ = 25.6 Ω

Finally, we shall determine the equivalent resistance of the group. This can be obtained as follow:

Equivalent Resistance of R₁ and R₃ (R₁ₙ₃) = 25.6 Ω

Resistor 2 (R₂) = 25.4 Ω

Equivalent Resistance (Rₑq) =?

Rₑq = R₁ₙ₃ + R₂ (series connection)

Rₑq = 25.6 + 25.4

Rₑq = 51 Ω

Therefore, the equivalent resistance of the group is 51 Ω.

4 0

3 years ago

A proton moving at 5.00 106 m/s through a magnetic field of magnitude 1.78 t experiences a magnetic force of magnitude 7.40 10-1

aliya0001 [1]

The magnetic part using the Lorentz force is: F = q v x B,
where v and B are vectors and v x B is the vector cross product.

Magnitude of the force: F = q v B sin(α)

So, sin(α) = F/( e v B), with e the proton charge.

This will give you a value for sin(α), and two potentials for its opposite.

You will now look for:

sin(α) = 7.40 10^-13/( 1.60 10^-19 * 5 10^6 * 1.78)
= 0.520

So either sin(α) = 0.502 or sin(α) = -0.502
The 1st α = 30.1 degrees or α = 150 degrees.
The 2nd α = 210 degrees or α = 330 degrees.
So we can say that 30.1 degrees and 330 degrees would be minimum and biggest on [0,360]

6 0

3 years ago