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3 years ago

If you have 222 g of radioisotope with a half-life of 5 days, how much isotope would remain after 15 days?

1 answer:

7 0

If the half life is 5 days, you would have to divide 222 by 2 3 times.
so 222/2 =111g
111/2 = 55.5g
55.5/2 = 27.75g

after four half life the mass would be
27.75/2
13.875g

the percent would be
13.875/222
= 6.25%

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If E=mc^2,solve for both m and c. Also, if m=80 and c=0.40 what is the value of E?

Pie

Answer:

$m = \frac{E}{c^2}$

$c = \sqrt{\frac{E}{m} }$

$E = 12.8 J$

Explanation:

Part 1: Solving for m

We are given that:

E = mc²

To solve for m, we will need to isolate the m on one side of the equation

This means that we will simply divide both sides by c²

$m = \frac{E}{c^2}$

Part 2: Solving for c

We are given that:

E = mc²

To solve for c, we will need to isolate the m on one side of the equation

This means that first we will divide both sides by m and then take square root for both sides to get the value of c

$c^2 = \frac{E}{m}\\ \\ c=\sqrt{\frac{E}{m}}$

Part 3: Solving for E

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m = 80 and c = 0.4

To get the value of E, we will simply substitute in the given equation:

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4 0

3 years ago

The prevailing atmospheric pressure on a plateau in Colorado is 0.706 atm. Express this pressure in pounds per square inch, kilo

noname [10]

Answer:

1. 10.37114 psi

2. 71.5178 KPa

3. 71517.8 Pa

4. 536.56 mmHg.

5. 21.12352 inHg

Explanation:

From the question given,

Pressure = 0.706 atm

The pressure in other units of measurement is obtained as follow:

1. Pressure in Psi

1 atm = 14.69 psi

Therefore, 0.706 atm = 0.706 x 14.69 = 10.37 psi

2. Pressure in KPa

1 atm = 101.3 kPa

Therefore, 0.706 atm = 0.706 x 101.3 = 71.5178 KPa

3. Pressure in Pa

1 atm = 1.013x10^5 Pa

Therefore, 0.706 atm = 0.706 x 1.013x10^5 = 71517.8 Pa

4. Pressure in mmHg

1 atm = 760mmHg

Therefore, 0.706 atm = 0.706 x 760 = 536.56 mmHg

5. Pressure in inHg

1 atm = 29.92 inHg

Therefore, 0.706 atm = 0.706 x 29.92 = 21.12352 inHg

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3 years ago

The specific heat of palladium is 0.239 J/g°C. How much heat (q) is released when a 10.0 g piece of platinum cools from 100.0°C

Andrej [43]

Answer:

119.5 J

Explanation:

First we calculate the temperature difference:

ΔT = 100 °C - 50 °C = 50 °C

Then we can calculate the heat released by using the following formula:

q = Cp * ΔT * m

Where q is the heat, Cp is the specific heat, ΔT is the temperature difference and m is the mass.

We input the data:

q = 0.239 J/g°C * 50 °C * 10.0 g

q = 119.5 J

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