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egoroff_w [7]
3 years ago
15

The private papers of what scientist had to be decontaminated for two years in the 1990's before being put on file at the Nation

al Library in Paris? 577 points
Physics
1 answer:
SashulF [63]3 years ago
3 0
The answer is Marie Skłodowska Curie (AKA Marie Curie). She <span>lived her life awash in ionizing radiation. She would be carrying bottles of the radium and polonium in the pocket of her coat and put them in her desk drawer. 
So even after a century, her papers are still radioactive. Since the</span><span> most general isotope of radium, which is radium-226, has a half life of 1,601 years.</span>
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A 0.14-MIN baseball is dropped from rest. It has a momentum of 0.90 kg⋅m/skg⋅m/s just before it lands on the ground.
nikitadnepr [17]

The time spent in the air by the ball at the given momentum is 6.43 s.

The given parameters;

  • <em>momentum of the ball, P = 0.9 kgm/s</em>
  • <em>weight of the ball, W = 0.14 N</em>

The impulse experienced by the ball is calculated as follows;

Ft = \Delta P

where;

Ft is impulse

\Delta P is change in momentum

The time of motion of the ball is calculated as follows;

t = \frac{\Delta P}{F} \\\\t = \frac{0.9 - 0}{0.14} \\\\t = 6.43 \ s

Thus, the time spent in the air by the ball at the given momentum is 6.43 s.

Learn more here:brainly.com/question/13468390

7 0
2 years ago
) Un círculo de 120 cm de radio gira a 600 rpm. Calcula: a) su velocidad angular
DIA [1.3K]

Responder:

20πrads ^ -1; 24πrads ^ -1; 0,1 seg; 10 Hz

Explicación:

Dado lo siguiente:

Radio (r) del círculo = 120 cm

600 revoluciones por minuto en radianes por segundo

(600 / min) * (2π rad / 1 rev) * (1min / 60seg)

(1200πrad / 60sec) = 20π rad ^ -1

Velocidad angular (w) = 20πrads ^ -1

Velocidad lineal = radio (r) * velocidad angular (w)

Velocidad lineal = (120/100) * 20πrad

Velocidad lineal = 1.2 * 20πrads ^ -1 = 24πrads ^ -1

C.) Período (T):

T = 2π / w = 2π / 20π = 0.1 seg

D.) Frecuencia (f):

f = 1 / T = 1 / 0.1

1 / 0,1 = 10 Hz

5 0
3 years ago
What is terrestrial radiation?
Feliz [49]
C) Radiation that comes from Earth...... Hope it helps, Have a nice day :)
6 0
2 years ago
Read 2 more answers
. A solenoid coil consists of a single layer of 250 circular turns of wire with each turn having a 0.02m radius. The axial lengt
Vinil7 [7]

Answer:

a)    L = 3.29 10⁻⁴ H,  b)U = 5.33 10⁻²  J

Explanation:

a) The inductance is a solenoid this given carrier

           L = \frac{N \ \phi_B }{I}

The magnetic field inside the solenoid is

          B = μ₀ \frac{N}{l}  i

hence the magnetic flux

          Ф_B = B. A = μ₀ \frac{N \ A}{l \ i}

we substitute in the expression of inductance

          L = N² μ₀ A /l

let's find the area of ​​each turn

          A = π r²

         A = π 0.02²

         A = 1.2566 10⁻³ m²

let's calculate

          L = 250² 4π 10⁻⁷ 1.2566 10⁻² / 0.3

          L = 3.29 10⁻⁴ H

b) The stored energy is

           U = ½ L i²

let's calculate

            U = ½ 3.29 10⁻⁴ 18²

            U = 5.33 10⁻²  J

5 0
3 years ago
This is a Physics practice question. How do i solve it?
Elena-2011 [213]

Answer:

P = 140000 [Pa]

Explanation:

To solve this problem we must remember that pressure is defined as the relationship between Force on the area of a body.

In this particular problem, we are given the force acting on the upper surface of the block, including the force exerted by the atmospheric pressure.

P = F/A

where:

P = pressure [Pa] (units of Pascals)

F = force = 3.5*10⁴ [N]

A = area = 0.25 [m²]

P = 3.5*10⁴/0.25

P = 140000 [Pa]

7 0
3 years ago
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