Please help me with 1&2

In 8,450 seconds, the number of radioactive nuclei decreases to 1/16 of the number present initially. What is the half-life (in

almond37 [142]

Answer:

<h2>2113 seconds</h2>

Explanation:

The general decay equation is given as $N = N_0e^{-\lambda t} \\\\$ , then;

$\dfrac{N}{N_0} = e^{-\lambda t} \\$ where;

$N/N_0$ is the fraction of the radioactive substance present = 1/16

$\lambda$ is the decay constant

t is the time taken for decay to occur = 8,450s

Before we can find the half life of the material, we need to get the decay constant first.

Substituting the given values into the formula above, we will have;

$\frac{1}{16} = e^{-\lambda(8450)} \\\\Taking\ ln\ of \both \ sides\\\\ln(\frac{1}{16} ) = ln(e^{-\lambda(8450)}) \\\\\\ln (\frac{1}{16} ) = -8450 \lambda\\\\\lambda = \frac{-2.7726}{-8450}\\ \\\lambda = 0.000328$

Half life f the material is expressed as $t_{1/2} = \frac{0.693}{\lambda}$

$t_{1/2} = \frac{0.693}{0.000328}$

$t_{1/2} = 2,112.8 secs$

Hence, the half life of the material is approximately 2113 seconds

7 0

2 years ago

After leaving the end of a ski ramp, a ski jumper lands downhill at a point that is displaced 68.3 m horizontally from the end o

inessss [21]

Answer:

a)52.58 m/s

b)56.13°

Explanation:

assume the upward direction as positive

x-component of the velocity = 29.3×cos33.6°=24.40 m/s (remain constant)

y-component of the velocity which is -29.3sin33.6°= -16.21 m/s

time of flight = 68.3/24.40= 2.7991 seconds

now, we can obtain final velocity in y-direction

$v_f_y= v_i_y-gt$

$v_f_y=-16.21-(-9.8)×2.7991$

=43.66 m/s

$v_0=\sqrt{29.3^2+43.66^2}$

=52.58 m/s

for direction

$tan^{-1}\frac{43.66}{29.3}$

56.13° from the horizontal

3 0

2 years ago

What property of an electromagnetic wave changes when the wave is encoded with analog information?

Licemer1 [7]

Answer:

Amplitude and Frequency

Explanation:

Analog signals are composed of continuous waves that can have any values for frequency and amplitude. These waves are smooth and curved.

Radio transmissions are a combination of two kinds of waves: audio frequency waves that represent the sounds being transmitted and radio frequency waves that "carry" the audio information. All waves have a wavelength, an amplitude and a frequency as shown in the figure. These properties of the wave allow it to be modified to carry sound information.

The two most common types of modulation used in radio are amplitude modulation (AM) and frequency modulation (FM). Frequency modulation minimizes noise and provides greater fidelity than amplitude modulation, which is the older method of broadcasting . Both AM and FM are analog transmission systems, that is, they process sounds into continuously varying patterns of electrical signals which resemble sound waves.

7 0

2 years ago

A young man exerted a force of 9000N on a stalled car but was unable to move it. How much work was done?

rodikova [14]

Answer:

No work was done at all.

Explanation:

Work is only done when a force is exerted and it moves an object. However, when the man exerted his force on the car, the car did not move at all. Therefore, no work was done.

7 0

3 years ago

Magnesium hydroxide is a common ___?

omeli [17]

Answer:

Magnesium hydroxide is the inorganic compound with the chemical formula Mg(OH)2. Magnesium hydroxide is a common component of antacids, such as milk of magnesia, as well as laxatives

Explanation:

pls mark brainliest

6 0

2 years ago

Read 2 more answers