A converging lens of focal length 20cm, forms a real image twice the size of the object. Calculate:
i) the power of the lens;
ii) the position of the image.

Answer

Resistivity R = K * L / A    where resistivity is constant for material, L the length of the material and A the area of the material

K = R * A / L     where R is the resistance of the material

That's a parallel circuit. (B)

When current from Point-A reaches the 3-way intersection just to the right of Point-B, it has to make a choice:  Either turn left, go through B, and light the lower bulb, or go straight and light the upper bulb.

A circuit that has any "decision" points in it is a parallel circuit.  What happens in the real world is:  The current splits up.  Some of the current that reaches the intersection turns left toward Point-B, and the rest of it goes straight up.

A series circuit is one in which there's only one possible path all the way around.  There are no intersections of more than 2 roads, and no electron ever has to decide which way to flow.

An open circuit is one in which there's a break somewhere along the line and electrons can't jump across it.  It's like a railroad where a big piece is cut out of the track somewhere.  So no trains can travel on that route, and there's no current flowing anywhere in the circuit.

I'm not so sure about a "combination" circuit.  I guess you could give that name to a complicated circuit that has some series parts and some parallel-parts.  Personally, I'd call that a "series-parallel" circuit.  But it really doesn't matter right now.  Whatever the word means, the circuit in the picture is definitely not a "combination" circuit.

Answer:

B. Parallel Circuits

Explanation:

A parallel circuit is constructed by connecting the terminals of all the individual load devices so that the same value of voltage appears across each component. In a parallel circuit, charge divides up into separate branches such that there can be more current in one branch than there is in another.

hope i helped

Answer:

that when two object interact, they apply forces to one another that are equal in magnitude and opposite in direction.

Explanation:

Newton's third law: the law of action and reaction

Answer:

The photon takes millions of years to reach the Surface of the sun while the Neutrinos travelling at the speed of light reaches the surface of the sun in approximately 2 seconds

The Photon is million year old while the neutrino is just some minutes old as observed by the student .

Explanation:

Although The Photon ( sunshine from the sun's surface ) heating up the student standing on the Earth's surface and the neutrinos discovered by the other student inside the gold mine are both formed in the Sun's core.

The difference between both are

The photon takes millions of years to reach the Surface of the sun while the Neutrinos travelling at the speed of light reaches the surface of the sun in approximately 2 seconds

The Photon is million year old while the neutrino is just some minutes old as observed by the student .

It's the velocity, but only the magnitude. It can't show the direction of the velocity. So it's better to call it speed.

Answer:

[tex]F = kmg \\ k = \frac{F}{mg} [/tex]

Explanation:

F = k . m . g

=> F = k . mg

[tex] = > k = \frac{F}{mg} (ans)[/tex]

Answer:

im pretty sure that it's (A.) High current

Explanation:

pf

not 100% sure, tho

Answer:

2.5 m/s²

Explanation:

The given parameters are;

The mass of the car, m = 2,000 kg

The radius of the car, r = 40.0 m

The coefficient of friction between the car tires and the road, μ = 0.500

The constant speed with which the car moves, v = 10.0 m/s

The normal reaction of the road on the car, N = The weight of the car;

∴ N = m × g

Where;

g = The acceleration due to gravity ≈ 9.81 m/s²

N ≈ 2,000 kg × 9.81 m/s² = 19,620 N

The frictional force, [tex]F_f[/tex] = μ × N

The centripetal force, [tex]F_c[/tex] = m·v²/r

The car moves without slipping when [tex]F_f[/tex] = [tex]F_c[/tex]

Therefore, [tex]F_f[/tex] = 0.500 × 19,620 N = 2,000 kg × [tex]v_{max}[/tex]²/40.0 m

∴ [tex]v_{max}[/tex] = √(0.500 × 19,620 N × 40.0 m/2,000 kg) ≈ 14.007 m/s

Therefore, the velocity with which the car moves, v < [tex]v_{max}[/tex]

The cars centripetal acceleration, [tex]a_c[/tex] = v²/r

∴ [tex]a_c[/tex] = (10.0 m/s)²/40.0 m = 2.5 m/s²

The cars centripetal acceleration as it goes round the turn, [tex]a_c[/tex] = 2.5 m/s².