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
belka [17]
3 years ago
7

Cobalt-60 has a half life of 5.25 years. If you started with a 40 gram sample of pure cobalt-60, how many grams of cobalt-60 wou

ld remain after 10.5 years?
Physics
1 answer:
s2008m [1.1K]3 years ago
6 0

Answer:

10 grams

Explanation:

A = A₀ (½)^(t / T)

A = 40 (½)^(10.5 / 5.25)

A = 40 (½)^2

A = 40 · ¼

A = 10

You might be interested in
The gravitational force of a star on an orbiting planet 1 is F1. Planet 2, which is twice as massive as planet 1 and orbits at t
Andrej [43]

Answer:

ratio = 1 : 4.5

Explanation:

If m₁ is the mass of the star and m₂ the mass of the planet, the force of gravity F₁ for planet 1 is given by:

F_1=\frac{Gm_1m_2}{r^2}

The force F₂:

F_2=\frac{Gm_1(2m_2)}{(3r)^2}

The ratio:

\frac{F_2}{F_1}=\frac{2}{9}

8 0
3 years ago
Which statement is true?
Maurinko [17]
The correct answer is<span> B.The speed of sound in air is directly proportional to the temperature of the air.

When the temperature increases so does the speed of sound. Sound is faster by </span>0.60 m/s for every higher degree in air temperature because the air density is reduced and the sound can travel faster.
8 0
3 years ago
Under what condition will a glass lens placed in a transparent medium becomes invisible??
Viktor [21]

Answer:

A lens placed in a transparent liquid becomes invisible because when refractive index of the material of the lens is equal to the refractive index of the liquid in which lens is placed under this condition no bending of light takes place when it travels from liquid to the lens, so both will start behaving like both are same things.

Explanation:

hope it helps :))

5 0
3 years ago
Which force would result in a balanced force for the
ohaa [14]

Answer:

F= 45 N

Explanation:

4 0
3 years ago
Which of the following is one way that an electric motor's rotation speed can be controlled?
malfutka [58]
Depending on which type of motor you're talking about, but the first 3 are true.  A stronger magnetic field in a DC motor will slow it down but increase its torque.
The amount of current in the motor will control the magnetic fields and therefore affect the speed (and torque).  In an induction motor, the rotational speed is given by n= \frac{120f}{p}  where f is the line frequency and p is the number of poles.  Thus fewer poles makes it go faster.
5 0
3 years ago
Read 2 more answers
Other questions:
  • what Karl Kraus meant by the thought? "You'd be surprised how hard it is to translate an action into thought"
    14·1 answer
  • Hint: This problem requires a train of logic. (1) Analyze force diagram, (2) use Newton’s Laws, and (3) solve the equations of m
    10·1 answer
  • Physics. How to solve this?
    13·1 answer
  • Have researchers have now been able to cool substances to absolute zero
    5·1 answer
  • Beta particles will:
    15·2 answers
  • A small wooden block with mass m1 is suspended from the lower end of a light cord that is l long. The block is initially at rest
    9·1 answer
  • A balloon-powered car rolls across the floor at a speed of 0.711 m/s. How long does it take to cover 8.25 m?
    8·1 answer
  • Tom has a mass of 50,000 g and runs up a flight of stairs 4 m high in 12.5 seconds.
    15·1 answer
  • A tire rotates 50 times in 2.5 seconds what is its period?​
    15·1 answer
  • A cat is sleeping on the floor in the middle of a 2.8-m-wide room when a barking dog enters with a speed of 1.40 m/s. As the dog
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!