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
Simora [160]
3 years ago
15

Calculate the activity of 60Co after 72hr, if you know the activity at time 0 is 35MBq (decay constant=0.001 day-1)?

Physics
1 answer:
Marianna [84]3 years ago
4 0

Answer:

The activity of cobalt-60 after 72 hours is 34.895 MBq

Explanation:

A(t) = Ao(0.5)^t/t1/2

A(t) is the activity of cobalt-60 after time t

Ao is the initial activity of cobalt-60 = 35 MBq

t is time taken to reduce in activity = 72 hours = 72/24 = 3 days

t1/2 is the half-life = 0.693 ÷ decay constant = 0.693 ÷ 0.001/day = 693 days

A(72) = 35(0.5)^3/693 = 35 × 0.5^0.00433 = 35 × 0.997 = 34.895 MBq

You might be interested in
3. A model rocket is launched straight upward at 58.8 m/s.
SIZIF [17.4K]

Let us assume that rocket only runs in initial energy and not using its own to flying.

Also , let upward direction is +ve and downward direction is -ve .

Initial velocity , u = 58.8 m/s .

Acceleration due to gravity , g=-9.8\ m/s^2 .

Final velocity , v - = 0 m/s .

We know , by equation of motion .

v^2-u^2=2gh\\\\2gh_{max}=0^2-58.8^2\\\\h_{max}=\dfrac{0^2-58.8^2}{-2\times 9.8}\\\\h_{max}= 176.4\ m

Hence, this is the required solution .

8 0
3 years ago
Which statements are true? Science is a collection of facts that does not evolve. We have gained all the knowledge we can from s
puteri [66]

Answer: Scientists observe natural events occuring around them. If a hypothesis is not veriffied by the results from the scientific method, scientists may redo the process or create a new hypothesis

Explanation:

4 0
3 years ago
What is harmonic motion
Tanzania [10]

Answer:  NNOOOOOOOOOOOOOOOOOOONONONO

Explanation: simple harmonic motion, in physics, repetitive movement back and forth through an equilibrium, or central, position, so that the maximum displacement on one side of this position is equal to the maximum displacement on the other side. The time interval of each complete vibration is the same. The force responsible for the motion is always directed toward the equilibrium position and is directly proportional to the distance from it. That is, F = −kx, where F is the force, x is the displacement, and k is a constant. This relation is called Hooke’s law.

A specific example of a simple harmonic oscillator is the vibration of a mass attached to a vertical spring, the other end of which is fixed in a ceiling. At the maximum displacement −x, the spring is under its greatest tension, which forces the mass upward. At the maximum displacement +x, the spring reaches its greatest compression, which forces the mass back downward again. At either position of maximum displacement, the force is greatest and is directed toward the equilibrium position, the velocity (v) of the mass is zero, its acceleration is at a maximum, and the mass changes direction. At the equilibrium position, the velocity is at its maximum and the acceleration (a) has fallen to zero. Simple harmonic motion is characterized by this changing acceleration that always is directed toward the equilibrium position and is proportional to the displacement from the equilibrium position. Furthermore, the interval of time for each complete vibration is constant and does not depend on the size of the maximum displacement. In some form, therefore, simple harmonic motion is at the heart of timekeeping.

3 0
2 years ago
Earth's gravitational pull just got threetimes stronger! what happens to your weight/
OLga [1]
Hold on and let's discuss this realistically.

Because of gravity, there are two forces between the Earth and me. One draws me toward the Earth. The strength of that force is what I call my "weight". The other force draws the Earth toward me, and has the same strength.

The strength of these forces depends on the masses of the Earth and me. If the strength just tripled, that means that at least one of us just picked up a lot more mass. If the Earth suddenly became three times as massive, then the weight of everything and everybody on it would suddenly triple, and I'm pretty sure it would be the end of all of us before too long.

If it was only MY mass that suddenly tripled, that would mean that I had gone tearing through my house and the neighbour's house, eating everything in sight including the 2 couches, 3 dogs, and 6 TVs. Naturally, just as you would expect, my weight changed from 207 to 621, and my skin is stretched really tight.
ooohhh
8 0
3 years ago
g Doppler Radar gathers information about precipitation by sending out pulses of ______ energy that is reflected back by the pre
allsm [11]

Answer:

Doppler Radar gathers information about precipitation by sending out pulses of ___Radio wave___ energy

7 0
3 years ago
Other questions:
  • A typical machine tests the tensile strength of a sheet of material cut into a standard size of 5.00 centimeters wide by 10.0 ce
    12·1 answer
  • a bus carrying a band and all their equipment has an initial velocity of 14 m/s. it accelerates for 3seconds
    7·1 answer
  • An object in free fall travels a distance s that is directly proportional to the square of the time t. If an object falls 1088 f
    10·1 answer
  • An evacuated tube uses an accelerating voltage of 40 kv to accelerate electrons to hit a copper plate and produce x rays. non-re
    5·2 answers
  • What is the difference between a permanent magnet and a temporary magnet
    10·2 answers
  • A 2.7 kg block of ice at a temperature of 0.0◦C and an initial speed of 6.5 m/s slides across a level floor. If 3.3 × 105 J are
    11·1 answer
  • How is a gravitational field around an object shown
    11·1 answer
  • If the purpose of electronic monitoring is to control offenders, it is a _____(1)_____, but if the purpose is to reintegrate off
    13·1 answer
  • Explain the concept of energy conversion as applied to the generation of electricity also known as electrical energy.​
    9·1 answer
  • ______ resources include biodiversity, energy, land and<br> soil, and water resources.
    7·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!