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4 years ago

We can see objecf in bright room because

Physics

2 answers:

aivan3 [116]4 years ago

8 0

Answer:

because there is a reflection due to light in the the room.

Explanation:

if if it's helped you please mark as brainliest and like and follow please

abruzzese [7]4 years ago

3 0

We can see objects in a bright room because, the object reflect the light falling on them

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What are plane mirrors ?

forsale [732]

Explanation:

Mirrors consist of reflecting surfaces that reflect light.

Reflection is a phenomenon of light wave (but also of other types of waves) in which a ray of light hits a surface, and then it bounces back into the original medium at a certain angle.

The direction of the reflected ray is determined by the law of reflection:

The incident ray, the reflected ray and the normal to the surface all lie in the same plane
The angle of reflection is equal to the angle of incidence (where both angles are measured between the ray and the normal to the surface)

A plane mirror is a type of mirror consisting of a straight surface. As a result, light incident perpendicular to the surface is reflected back exactly in the opposite direction.

The image formed by a plane mirror is:

- The same size as the object

- Virtual (it is located behind the mirror)

- Laterally inverted

- Upright

3 0

4 years ago

Please answer all of them <br>I'll give brainly if answer for points will be reported

enyata [817]

Answer:

Level 1-

1. It depends of the sense and the magnitude of the force

2. Electric force

3. A contact force need to touch to act in the object, like push a box for example. A non-contact force don't need to touch to act in the object, like an magnet attracting other magnet

4. The pressure is the force divided by the area. The unit for pressure in the international system is Pascal

5. Because the pressure is applied in all the surface of our bodies, so the force is divided by the surface area of our bodies.

Level 2-

1. The balloons stick to the walls because when she rubbed they in her clothes they earned eletric charge, and when they touched the wall, the electric charges of the wall got polarized and it creats a attraction force.

The same happened with the water stream. The balloons were charged with electric charges and the water was attracted by it.

2. Mass is the amount of matter, it's an scalar quantity. Weight is the force created by the attraction of a massive body as the Earth, and another body as a human, and a force is a vector

3. It's for increase the surface area, so the pressure will be decreased

4. When a person pulls up the syringe plunger the pressure inside the syringe is smaller than the pressure outside, so the pressure push the liquid into the syringe

5. a) The stream of the top is falling closer than the stream from the bottom, causa in the top the pressure is lower than in the bottom. In the bottom, beyond the air pressure, it has also the whole column of water making more pressure, so it goes far.

b) The streams are all near because the holes are in the same height, so the pressure is divided for all the holes.

Level 3-

1. The girl.

pressure of the girl: 50/1 = 50

pressure of the man: 100/25 = 4

pressure of the elephant: 4500/250 = 18

So, the girl exerts more pressure.

2. When the can is heated the air inside expands and get out of it. If you seal the mouth of the can, the air cannot return to inside it, and when it get colder the air inside will shrink back to the normal volume, so it will occupy less space and the outside pressure will exerts a force and deform the can.

4 0

3 years ago

Equation of uniformly accelerated motion

Romashka [77]

This means acceleration a is constant.

Let

a) vo be the initial speed, at t=0

b) v be the final speed after time t

c) d distance travelled in time t

Then we have:

a) v=vo+a×t

b) v²=vo²+2×a×d (Galilei's equation)

c) d=vo×t+a×t²/2

d) average speed vm=(vo+v)/2

3 0

4 years ago

calculate the time rate of change in air density during expiration. Assume that the lung has a total volume of 6000mL, the diame

kipiarov [429]

Answer:

The time rate of change in air density during expiration is 0.01003kg/m³-s

Explanation:

Given that,

Lung total capacity V = 6000mL = 6 × 10⁻³m³

Air density p = 1.225kg/m³

diameter of the trachea is 18mm = 0.018m

Velocity v = 20cm/s = 0.20m/s

dv /dt = -100mL/s (volume rate decrease)

= 10⁻⁴m³/s

Area for trachea =

$\frac{\pi }{4} d^2\\= 0.785\times 0.018^2\\= 2.5434 \times10^-^4m^2$

0 - p × Area for trachea =

$\frac{d}{dt} (pv)=v\frac{ds}{dt} + p\frac{dv}{dt}$

$-1.225\times2.5434\times10^-^4\times0.20=6\times10^-^3\frac{ds}{dt} +1.225(-1\times10^-^4)$

⇒ $-0.623133\times10^-^4+1.225\times10^-^4=6\times10^-^3\frac{ds}{dt}$

$\frac{ds}{dt} = \frac{0.6018\times10^-^4}{6\times10^-^3} \\\\= 0.01003kg/m^3-s$

ds/dt = 0.01003kg/m³-s

Thus, the time rate of change in air density during expiration is 0.01003kg/m³-s

3 0

3 years ago

Read 2 more answers

A slingshot fires a pebble from the top of a building at a speed of 15.0 m/s. The building is 30.0 m tall. Ignoring air resistan

dimaraw [331]

Answer:

V=28.5m/s

b=V=28.5m/s

c=V=28.5m/s

Explanation:

A slingshot fires a pebble from the top of a building at a speed of 15.0 m/s. The building is 30.0 m tall. Ignoring air resistance, find the speed with which the pebble strikes the ground when the pebble is fired.

(a) horizontally,

(b) vertically straight up,

(c) vertically straight down.

u=15m/s

yi=30m

v=?

yf=0

system=pebble+earth

workdone=0

chnage in energy=0

ki+Ui=Kf+Ui

K=kinetic energy

U=potential energy

1/2mv^2+mgyf=1/2mu^2+mgyi

V^2=u^2+2gyi

V= $\sqrt{15^2+2*9.81*30}$

V=28.5m/s

b. and c will be the same as a. because the magnitude of the kinetic energy is dependent on the velocity and not the magnitude which the pebble is tilted at

3 0

3 years ago

We can see objecf in bright room because​

We can see objecf in bright room because