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4 years ago

Which collects light in a reflecting telescope?

Physics

2 answers:

Temka [501]4 years ago

8 0

Answer: Option a, concave lens.

Explanation: The object that collects the light in a reflecting telescope is "kinda" concave lens that collects the light and directs it to a mirror, that is where the observer can see. So the correct answer is option a.

Alecsey [184]4 years ago

4 0

Concave lens. These are used in making the objectives of reflection telescopes

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If the designers of submarines do not appropriately account for hydrostatic pressure,

andre [41]

Answer:

A) the pressure could crush the submarine

Explanation:

The submarines are mainly used for defense purposes.
In world war 1 and 2 the submarines played a vital role in the war.
The submarines work according to the principle of buoyancy.
According to this principle, when seawater is filled inside the tank in a required amount, the submarines sink.
When the seawater is expelled, the submarine rises to above the sea.
Most of the time, it dives deep into the sea, the hydrostatic pressure should be taken into account.
If the hydrostatic pressure is not considered, the pressure could crush the submarine.

7 0

3 years ago

Which travels at a greater speed, visible or infrared light?

Ksju [112]

Infrared light because it is barely able to be seen

7 0

3 years ago

An electron is trapped between two large parallel charged plates of a capacitive system. The plates are separated by a distance

Lorico [155]

Answer:

The electron will get at about 0.388 cm (about 4 mm) from the negative plate before stopping.

Explanation:

Recall that the Electric field is constant inside the parallel plates, and therefore the acceleration the electron feels is constant everywhere inside the parallel plates, so we can examine its motion using kinematics of a constantly accelerated particle. This constant acceleration is (based on Newton's 2nd Law:

$F=m\,a\\q\,E=m\,a\\a=\frac{q\,E}{m}$

and since the electric field E in between parallel plates separated a distance d and under a potential difference $\Delta V$ , is given by:

$E=\frac{\Delta\,V}{d}$

then :

$a=\frac{q\,\Delta V}{m\,d}$

We want to find when the particle reaches velocity zero via kinematics:

$v=v_0-a\,t\\0=v_0-a\,t\\t=v_0/a$

We replace this time (t) in the kinematic equation for the particle displacement:

$\Delta y=v_0\,(t)-\frac{1}{2} a\,t^2\\\Delta y=v_0\,(\frac{v_0}{a} )-\frac{a}{2} (\frac{v_0}{a} )^2\\\Delta y=\frac{1}{2} \frac{v_0^2}{a}$

Replacing the values with the information given, converting the distance d into meters (0.01 m), using $\Delta V=100\,V$ , and the electron's kinetic energy:

$\frac{1}{2} \,m\,v_0^2= (11.2)\,\, 1.6\,\,10^{-19}\,\,J$

we get:

$\Delta\,y= \frac{1}{2} v_0^2\,\frac{m (0.01)}{q\,(100)} =11.2 (1.6\,\,10^{-19})\,\frac{0.01}{(1.6\,\,10^{-19})\,(100)}=\frac{11.2}{10000} \,meters=0.00112\,\,meters$ Therefore, since the electron was initially at 0.5 cm (0.005 m) from the negative plate, the closest it gets to this plate is:

0.005 - 0.00112 m = 0.00388 m [or 0.388 cm]

8 0

4 years ago

What is necessary condition for the conservation of momentum?

MrRa [10]

N<span>o net external force acts on the system </span>

6 0

3 years ago

What is inertia?

EleoNora [17]

Answer: C. The tendency of an object to maintain its state of motion.

Explanation: Newton’s first law: If a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at constant speed unless it is acted upon by a force.

4 0

3 years ago