What Methods Do All Scientists Have in Common?

1. The thermal convection that drives plate motion is caused by

noname [10]

Subduction I believe

6 0

3 years ago

A scientist begins with 100 milligrams of a radioactive substance that decays exponentially. After 33 hours, 50 mg of the substa

Hoochie [10]

Answer:

$m\approx34.99$

Explanation:

Radioactive decay behaves according to the law of exponential decay:

$m(t)=m_0*e^{-rt}$

Where:

$r=Decay\hspace{3}rate$

$t=Time(In\hspace{3}days)$

$m_0=Initial\hspace{3}amount\hspace{3}of\hspace{3}substance$

$m(t)=Amount\hspace{3}of\hspace{3}substance\hspace{3}at\hspace{3}time\hspace{3}t$

So we need to find the decay rate r. Let's find it using the equation and the data provide, but first, we need to convert the hours in days:

$50h*\frac{1day}{24h}=\frac{25}{12}day\\ 33h*\frac{1day}{24h} =\frac{11}{8}day$

Now for $t=\frac{11}{8},m=50$ then:

$m(\frac{11}{8} )=100*e^{-r(\frac{11}{8}) } =50$

Divide both sides by 100:

$e^{-r(\frac{11}{8}) } =\frac{1}{2}$

Take the natural logarithm of both sides:

$-\frac{11}{8}x=ln(\frac{1}{2} )$

Multiply both sides by -8/11:

$x=\frac{-8ln(\frac{1}{2} )}{11} \approx0.504107$

Now we have found the rate decay r, let's find how many milligrams will remain after 59 hours (25/12 day):

$m(\frac{25}{12} )=100*e^{-0.504107*\frac{25}{12}) } =100*e^{-1.050222917}=34.98597508\approx35.99$

4 0

3 years ago

Suppose you had two magnets, who were attracted to each other, and you brought them together. Then took them apart by separating

IgorLugansk [536]

Answer:4. Two charged objects have a repulsive force of 0.080 N. If the distance separating the objects is tripled, then what is the new force? Explanation: The electrostatic force is inversely related to the square of the separation distance.

Explanation:

8 0

3 years ago

Calculate the coefficient of friction of a 12kg object that has a force of friction of 3N

postnew [5]

Answer:

0.026

Explanation:

The force of friction acts in the direction perpendicular to the norm force of the surface on which the object rests, induced by gravity. The magnitude of the friction force is

(Friction) = (mass) x (gravitational acceleration g) x (coefficient of friction)

from which the coefficient of friction can be determined:

(coefficient of friction) = (Friction) / ((mass)x(g)) = 3 N / (12 kg * 9.8 m/s^2) = 0.026

3 0

3 years ago

A lab group was given a candle, a match, a strip of cloth, tongs, and a metal can. They were asked to use these materials to mod

Troyanec [42]

Answer:

The materials with which the lab group are to use for the model includes;

i) A candle

ii) A match

iii) A strip of cloth

iv) Tongs

v) A metal can

The processes the lab group are to model are;

a) Conduction

b) Convection

c) Radiation

The procedure the lab group can use to do this is outlined as follows;

1) Tie the piece of cloth around the metal can with a strip of the cloth extending past the bottom of the can

2) Hold the metal can in with the aid of the tongs

3) Light the candle with the match

4) Place the metal can over over the burning candle so that it does not touch the flame

5) While holding the can with the tongs, ensure that the strip of cloth hanging by the side of the can does not come in contact with the flame

Conduction

Conduction heat transfer is observed by the rising temperature of the tongs that is in the contact with the can

Convection

Convection heat transfer is observed by the rising temperature of the can that is placed in the path of the rising convection current from the candle wax

Radiation

Radiation heat transfer is observed by the shrinking of the piece of cloth placed beside the candle flame

Explanation:

3 0

3 years ago