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2 years ago

Why is a concave mirror is used a reflector in a torch light?

Physics

2 answers:

denis-greek [22]2 years ago

6 0

Answer:

Below:

Explanation:

A concave mirror is used as a torch reflector. ... When a light bulb is placed at the focus of a concave mirror reflector, the diverging light rays of the bulb are collected by the reflector. These rays are then reflected to produce a strong, parallel-sided beam of light.

Hope it helps...

It's Miss-Muska

tatiyna2 years ago

4 0

Answer:

diverging light rays of the bulb are collected by the reflector.

Explanation:

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A hydraulic press has one piston of diameter 4.0 cm and the other piston of diameter 8.0 cm. What force must be applied to the s

yan [13]

Answer:

The force is $F_1 = 400.8 \ N$

Explanation:

From the question we are told that

The first diameter is $d_1 = 4.0 \ cm = 0.04 \ m$

The second diameter is $d_2 = 8.0 \ cm = 0.08 \ m$

Generally the first area is

$A_1 = \pi * \frac{d^2_1 }{4}$

=> $A_1 = 3.142 * \frac{0.04^2}{4}$

=> $A_1 = 0.00126 \ m^2$

The second area is

$A_2 = \pi * \frac{d^2_2 }{4}$

$A_2 = 3.142 * \frac{0.08^2}{4}$

$A_2 = 0.00503 \ m^2$

For a hydraulic press the pressure at both end must be equal .

Generally pressure is mathematically represented as

$P = \frac{F}{A}$

$\frac{F_1}{A_1 } = \frac{F_2}{A_2 }$

=> $F_1 = \frac{1600}{0.00503} * 0.00126$

=> $F_1 = 400.8 \ N$

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2 years ago

A weight suspended from a spring is seen to bob up and down over a total distance of 20 centimeters twice each second.

Tom [10]

"Twice each second" means "2 per second". Frequency = 2 Hz.

Period = time for one bounce = 1 second

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2 years ago

Point charges q1=+2.00μC and q2=−2.00μC are placed at adjacent corners of a square for which the length of each side is 5.00 cm.

8_murik_8 [283]

The electric potential is a scalar unit, so we don't have to struggle with the vectors. The formula that gives electric potential is

$V = \frac{1}{4\pi\epsilon_0}\frac{q}{r}$

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$V_a = \frac{1}{4\pi\epsilon_0}\frac{q_1}{r_1} + \frac{1}{4\pi\epsilon_0}\frac{q_2}{r_2}$

The distance from the center of the square to one of the corners is $\sqrt2 L/2 = 0.035m$

$V_a = \frac{1}{4\pi\epsilon_0}\frac{2\times10^{-6}}{0.035} + \frac{1}{4\pi\epsilon_0}\frac{-2\times10^{-6}}{0.035} = 0$

The answer is zero, because the point charges are at equal distances and their magnitudes are also equal but their directions are opposite.

2) $V_b = \frac{1}{4\pi\epsilon_0}\frac{q_1}{r_1} + \frac{1}{4\pi\epsilon_0}\frac{q_2}{r_2}$

$r_1 = 0.05\sqrt2m\\r_2 = 0.05m$

$V_b = \frac{1}{4\pi\epsilon_0}\frac{2\times10^{-6}}{0.05\sqrt2} + \frac{1}{4\pi\epsilon_0}\frac{-2\times10^{-6}}{0.05}\\V_b = \frac{1}{4\pi\epsilon_0}\frac{2\times10^{-6}}{0.05} (\frac{1}{\sqrt2}-1)\\V_b = \frac{1}{4\pi\epsilon_0} (4\times 10^{-5})(-0.29)\\V_b = (-\frac{2.9\times10^{-6}}{\pi\epsilon_0})[tex]3) The work done on q3 by q1 and q2 is equal to the difference between energies. This is the work-energy theorem. So,[tex]W = U_b - U_a$

$U = \frac{1}{4\pi\epsilon_0}\frac{q_1q_3}{r} = Vq_3$

$W = q_3(V_b - V_a) = q_3(V_b - 0)\\W = (-2\times10^{-6})(-\frac{2.9\times10^{-6}}{\pi\epsilon_0})\\W = \frac{5.8\times10^{-12}}{\pi\epsilon_0}$

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How are kinetic energy potential energy and thermal energy in a substance related?

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The energy associated with an object's motion is called kinetic energy. ... This is also called thermal energy – the greater the thermal energy, the greater the kinetic energy of atomic motion, and vice versa.

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Why is a concave mirror is used a reflector in a torch light?​

Why is a concave mirror is used a reflector in a torch light?