All categories

3 years ago

Greg is giving a slide show presentation to a large audience. How might a laser best help him with the presentation?

Physics

2 answers:

gizmo_the_mogwai [7]3 years ago

3 0

Explanation :

The full form of laser is Light Amplification by Stimulated Emission of Radiation. It has particles of very high energy. It points in one direction.

Greg is giving a slide show presentation to a large audience. It is very important to make the presentation informative. By using a laser, we can focus on the important part of the presentation. So that we can highlight the important points.

Bogdan [553]3 years ago

3 0

Answer: When giving a slide show presentation we usually use a projector and a projection screen to show it.

Sometimes, Greg will need to "point" to some graph, image, equation, or something like that in order to drag the audience's attention in such a part.

If Greg went in front of the screen to signalize the part he wants, he will project a shadow on the screen, and this may be troublesome for some of the audience.

A laser comes handy here because Greg does not even need to move to point the laser in the part of the screen he wants, and it does not project a shadow or anything in the screen (The laser emits a "column" of coherent photons, that don't interact with the light of the projector), so it's very useful to signalize points as he speaks, which also allows him to not lose the flow of the presentation.

You might be interested in

How will the magnetic field of a straight wire carrying a constant current interact with the needle of a compass? Does the inter

Yuki888 [10]

Answer:

the needle will direct its North South according to the magnetic field of current carrying wire.

Explanation:

A current carrying wire always has a magnetic field around it, in circular loops. This magnetic field will be either clockwise or anticlockwise depending on the direction of current.

Right hand rule tells the direction. Place the current carrying wire in your right hand with thumb pointing the direction of current. Curl of the fingers tell the direction of current.

When the needle gets in the vicinity of the field, its poles aligns itself with the field. (previous position of the compass needle has no effect on its position in the field). The north pole and south pole will be set in the direction of magnetic field.

The distance between the needle and wire does effect the strength (accuracy) of the needle position. Strong field will create strong deflection of the needle whereas when the distance from wire increases, field weakens, thus the deflection of needle will be weak.

5 0

3 years ago

Concrete is pumped from a cement mixer to the place it is being laid, instead of being carried in wheelbarrows. The flow rate is

max2010maxim [7]

Answer:

a. 2.4 ×109 N ⋅ m2/s

b. 48.3 N⋅s /m2

c. 8.00×104W

Explanation:

See Attached file for explanation

3 0

3 years ago

A motorcycle starts to move from rest. If the velocity of the motorcycle becomes 90 km/hr

bagirrra123 [75]

Explanation:

90 kmhr—1 x 1000/3600 = 25ms—1

U = 0 ms—1

V = 25ms—1

t = 10 s

a = ?

a = V - U/t

a = 25 - 0/10

a = 25/10

a = 2.5 ms—1

6 0

2 years ago

Pure silicon contains approximately 1.0 X 1016 free electrons per cubic meter. (

Margarita [4]

A. The formula for mean free time is:

t = V/(4π√2 r²vN)
where
N = 1×10¹⁶ molecules (per m³)
V = 1 m³
r = 111×10⁻⁷m (atomic radius of silicon)

Let's solve for v first:
v = √(3RT/M) = √(3(8.314 m³·Pa/mol·K)(25 + 273 K)/28.1 g/mol Si)
v = 16.26 m/s

t = (1 m³)/(4π√2 (111×10⁻⁷m)²(16.26 m/s)(1×10¹⁶ molecules))
t = 2.81×10⁻9 s

Pure silicon has a high resistivity relative to copper because copper is a conductor, while silicon is a semi-conductor. 

3 0

3 years ago

A 1232 kg car moving north at 25.6 m/s collides with a 2028 kg car moving north at 17.5 m/s . They stick together. In what direc

Citrus2011 [14]

Answer:

I. Angle = 41.7° Northeast.

II. Vr = 7.08m/s

Explanation:

Let the two cars be denoted by A and B

Given the following data;

Mass of car A = 1232 Kg

Velocity of car A = 25.6 m/s

Mass of car B = 2028 Kg

Velocity of car B = 17.5m/s

First of all, we would solve for momentum;

Momentum = mass × velocity

Momentum, M1 = 1232 × 25.6

Momentum, M1 = 31539.2 Kgm/s

Momentum, M2 = 2028 × 17.5

Momentum, M2 = 35490 Kgm/s

Now, let's find the resultant momentum using the Pythagoras theorem;

R² = M1² + M2²

R² = 31539.2² + 35490²

R² = 994721136.6 + 1259540100

R² = 2254261237

Taking the square root of both sides, we have

Resultant momentum, R = 47479.06 Kgm/s

To find the direction;

Angle = tan¯¹(M1/M2)

Angle = tan¯¹(31539.2/35490)

Angle = tan¯¹(0.89)

Angle = 41.7° Northeast.

To find the speed;

R = (M1 + M2)Vr

47479.06 = (31539.2 + 35490)Vr

47479.06 = 67029.2Vr

Vr = 47479.06/67029.2

Vr = 7.08m/s

6 0

2 years ago