1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
VladimirAG [237]
3 years ago
7

Can someone help me with this Physics question please?

Physics
2 answers:
Ghella [55]3 years ago
7 0

How many half-lifes is 49.2 years ?

(49.2 years) / (12.3 years per half-life)  =  4 half-lifes.

In 4 half-lifes, (1/2) · (1/2) · (1/2) · (1/2) of the original sample remains.

That's (1/2⁴) or (1/16) of the original.

(1/16) of 48.0 mg  =  <em>3 mg</em> .

=======================

Step-by-step:

== Start with 48 mg .

== After one half-life, 24 mg remains.

== Then, after the second half-life, 12 mg remains.

== Then, after the third half-life, 6 mg remains.

== Then, after the fourth half-life, <em>3 mg</em> remains.

strojnjashka [21]3 years ago
6 0

Answer:

Explanation:

The formula for this, the easy one, is

N=N_0(\frac{1}{2})^{\frac{t}{H} where No is the initial amount of the element, t is the time in years, and H is the half life. Filling in:

N=48.0(\frac{1}{2})^{\frac{49.2}{12.3} and simplifying a bit:

N=48.0(.5)^4 and

N = 48.0(.0625) so

N = 3 mg left after 12.3 years

You might be interested in
Andre the Giant and Thumbelina are standing in the middle of an ice-skating rink facing each other. Andre the Giant pushes Thumb
IceJOKER [234]
I don't know for sure but i think that it is because the force him pushing her pushed him back as well

Hope i helped

3 0
3 years ago
Read 2 more answers
An Olympic track runner starts from rest and has an acceleration of 2.4 m/s2 for 3.6 s, then has zero acceleration for the remai
rjkz [21]

Answer:

The runner's speed at the following times would remain 8.64 m/s.

Explanation:

Acceleration definition: Acceleration is rate of change in velocity of an object with respect to time.

In this case, after 3.6 seconds the acceleration is zero, it means that the velocity of the runner after 3.6 seconds is not changing and it will remain constant for the remainder of the race. Now, we have to find the velocity of the runner that he had after 3.6 seconds and that would be the runner's speed for the remainder of the race. For this we use first equation of motion.

First equation of motion:        Vf = Vi + a×t

Vf stands for final velocity

Vi stands for initial velocity

a stands for acceleration

t stands for time

In the question, it is mentioned that the runner starts from rest so its initial velocity (Vi) will be 0 m/s.

The acceleration (a) is given as 2.4 m/s²

The time (t) is given as 3.6 s

Now put the values of Vi, a and t in first equation of motion

                       Vf = Vi + a×t

                       Vf = 0 + 2.4×3.6

                       Vf = 2.4×3.6

                       Vf = 8.64 m/s

So,the runner's speed at the following times would remain 8.64 m/s.

5 0
3 years ago
Terry usually rides his bike at 15mph. If his speed is reduced by 3 mph , how far can he ride in 1.7 hours ?
kakasveta [241]
105 miles because you have to use the gif arable
7 0
3 years ago
Consider a model of a hydrogen atom in which an electron is in a circular orbit of radius r = 5.92×10−11 m around a stationary p
DaniilM [7]

Answer:

2.068 x 10^6 m / s

Explanation:

radius, r = 5.92 x 10^-11 m

mass of electron, m = 9.1 x 10^-31 kg

charge of electron, q = 1.6 x 10^-19 C

As the electron is revolving in a circular path, it experiences a centripetal force which is balanced by the electrostatic force between the electron and the nucleus.

centripetal force = \frac{mv^{2}}{r}

Electrostatic force = \frac{kq^{2}}{r^{2}}

where, k be the Coulombic constant, k = 9 x 10^9 Nm^2 / C^2

So, balancing both the forces we get

\frac{kq^{2}}{r^{2}}=\frac{mv^{2}}{r}

v=\sqrt{\frac{kq^{2}}{mr}}

v=\sqrt{\frac{9\times 10^{9}\times1.6\times 10^{-19}\times 1.6\times 10^{-19}}{9.1\times 10^{-31}\times 5.92\times10^{-11}}}

v = 2.068 x 10^6 m / s

Thus, the speed of the electron is give by  2.068 x 10^6 m / s.

6 0
3 years ago
Compare the maximum rate of heat transfer to the basal metabolic rate by converting a bmr of 88 kcal/hr into watts. what is the
elena-14-01-66 [18.8K]

Explanation :

It is given that,

BMR i.e basal metabolic rate is 88 kcal/hr. So, BMR in watts is converted by the following :

We know that, 1 kilocalorie = 4184 joules

So, 1\ kcal/h=\dfrac{1\times 4184\ J}{3600\ sec}

1\ kcal/h=1.16\ J/sec

J/sec is nothing but watts.

So, 1\ kcal/h=1.16\ watts

and 88\ kcal/h=88\times 1.16\ watts = 102.08\ watts

So, it can be seen that the body can accommodate a modes amount of activity in hot weather but strenuous activity would increase the metabolic rate above the body's ability to remove heat.

8 0
3 years ago
Other questions:
  • If the federal government imposed an obligation on Texas to retrofit all its oil and gas pipelines with modern technology to eli
    15·1 answer
  • At which life cycle stage are stars most stable
    11·2 answers
  • A current of 3.60A flows for 15.3s through a conductor. Calculate the number of electrons that pass through a point in the condu
    15·1 answer
  • The current in a hair dryer measures 15.0 amps. The resistance of the hair dryer is 8 ohms. What is the voltage?
    6·2 answers
  • Where is the frequency of infrasound in relation to the range of a human's ability to hear?
    12·1 answer
  • A car moving at a speed of 20m/s has a kinetic energy of 300,000 J. What is the car’s mass?
    8·1 answer
  • y’all I would rlly appreciate if y’all gave me the answers to all my questions. My cousin has over 200 assignments she hasn’t do
    7·1 answer
  • A laser beam is incident on two slits with a separation of 0.180 mm, and a screen is placed 5.05 m from the slits. If the bright
    11·1 answer
  • What is the difference between magnetic flux and magnetic flux linkage?​
    14·1 answer
  • Red Riding Hood sat down to rest and placed her 1.20-kg basket of goodies beside her. A wolf came along, spotted the basket, and
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!