If the half-life of a radioactive sample is 11 years, it will take 37.06 years for the sample to decay to 25%.
What number of half lives have passed if there is 25% radioactivity left?Cobalt-60 has a half-life of 5.27 years, meaning that 50% of it is still present after that time (one half-life), 25% is still present after that time (two half-lives), 12.5% is still present after that time (three half-lives), and so on.
How long will it take 131 I sample to decay by 50%?Iodine-131, for instance, is a radioisotope with an 8-day half-life. By emitting beta particles, it decomposes into xenon-131. Any sample of iodine-131 will have half of its atoms destroyed after eight days.
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What is the power of a refrigerator with voltage 110 V and
current 0.8 A?
Answer: 88
Explanation:
If both cars are the same mass and hit each other at the same speed (in opposite directions):
1.) They both come to a stop.
2.) They come out of the collision at random speeds.
3.) They come out of the collision at the same speeds they entered it.
4.) They come out of the collision at the same velocities they entered it.
A cog system on the beginning segment of a roller coaster needs to get 29 occupied cars up a 120-m vertical rise over a time interval of 60 s. Each car experiences a gravitational force of 5900 N. The cars start at rest and end up moving at 0.50 m/s.
Answer:
Hello your question has some missing part attached below is the missing part
How much work is done by the cog system on the cars?
answer : 2.053 * 10^7 J
Explanation:
Total weight of car ( wT ) = 5900 * 29 = 171100 N
mass of car ( mT ) = wT / g = 171100 / 9.81 = 17459.18 kg
Hence work done by the cog system on the cars
W = ( KE[tex]_{2}[/tex] + PE[tex]_{2}[/tex] ) - ( KE[tex]_{1}[/tex] + PE[tex]_{1}[/tex] )
= ( 1/2 mv^2 + mgh ) - ( 0 )
= ( 1/2 * 17459.18 * 0.50^2) + ( 17459.18 * 9.81 * 120 )
= 2.053 * 10^7 J
can someone help me please? thank you
the statement from which investigation is an example of repetition? *answer choices in picture*
Answer:
vestigation 4
Explanation:
2 What is the net force on an object when you combine a force of 17 N north with a force of 9 N north?
Be sure to include the direction of the force.
Answer:
5N NORTH
Explanation:right on edge
ممكن حل بسرعة
please help
Answer:
I could help but i dont speak or understand a word of Arabic im so sorry.
Explanation:
If sound waves require a medium (material) to vibrate in order to produce a sound, can sound waves travel in outer space? Why or why not?
Sound waves requires a medium (material) to vibrate in order to produce a sound. So sound waves cannot travel in outer space as it is vacuum.
Which of the following situations best represents a set of balanced forces?
Group of answer choices
A 12 N of force pulling left while a 22 N of force pulls right.
A 6 N of force pulling left while a 10 N of force pulls right.
A 2 N force and a 10 N force pulling left while a 12 N force pulls right.
A 22 N force pulling left while a 6 N force and a 12 N force pulls right.
Answer:
A 2 N force pulling and a 10 N force pulling left while a 12N force pulls right.
If spring has a spring constant of 500 N/m and is stretched .50 meters,how much energy is stored in the spring ((show work for full credit, show equation))
Answer:
The energy stored is: 62.5 Joules
Explanation:
Given
[tex]k = 500N/m[/tex] --- spring constant
[tex]x = 0.5m[/tex] --- stretch
Required
The amount of energy
This is calculated as:
[tex]U = \frac{1}{2} kx^2[/tex]
[tex]U = \frac{1}{2} * 500N/m * (0.5m)^2[/tex]
[tex]U = 250N/m * (0.5m)^2[/tex]
[tex]U = 62.5\ J[/tex]
Which material transmits the most visible light?
A.Sunglass lens
B.Mirror
C.Clear glass
D.Black cloth
Answer:
c
Explanation:
First term / second mid Exam [1433/ 1434] Q12. A conductor of radius I, length and resistivity p has resistance R. What is the new resistance if it is stretched to 4 times its original length?
Answer:
R' = 4R
Hence, the resistance increases to four times its initial value as well.
Explanation:
The resistance of a conductor in terms of its physical dimensions can be given by the following formula:
[tex]R = \frac{\rho L}{A}\\[/tex] _______ equation (1)
where,
R = Resistance of the conductor
ρ = resistivity of the material of the conductor
L = Length of the conductor
A = Cross-sectional Area of the conductor
Now, if the length of the conductor is increased to four times, keeping other values constant, then:
[tex]R' = \frac{\rho L'}{A}\\\\R' = \frac{\rho (4L)}{A}\\\\R' = 4\frac{\rho L}{A}[/tex]
using equation (1):
R' = 4R
Hence, the resistance increases to four times its initial value as well.
A boy who is riding his bicycle, moves with an initial velocity of 5 m/s. ten second later, he is moving at 15 m/s. what is his acceleration
[tex]\Large {{ \sf {Question :}}} [/tex]
A boy who is riding his bicycle, moves with an initial velocity of 5 m/s. Ten second later, he is moving at 15 m/s. What is his acceleration?[tex]\Large {{ \sf {Given :}}} [/tex]
Initial Velocity (u) - 5 m/sFinal Velocity (v) - 15 m/sTime (t) - 10 sec[tex]\Large {{ \sf {Formulae :}}} [/tex]
If the velocity of an object changes from an initial value u to the final value v in time t, the acceleration a is, [tex]a \: = \frac{v - u}{t} [/tex][tex]\Large {{ \sf {Step-by-step explanation :}}} [/tex][tex]a \: = \frac{v - u}{t} \\ or \: \: a = \frac{(15 - 5)}{10} m \: s^{ - 2} \\ or \: \: a \: = \frac{10}{10}m \: s^{ - 2} \\ or \: \: a = 1m \: s^{ - 2} [/tex]
[tex]\Large {{ \sf {Answer :}}} [/tex]
His acceleration is [tex]1m \: s^{ - 2} [/tex]1. A +4 nC charge is placed at a distance r from another charge. If the charge experiences a force of 6000 N, what is the electric field intensity E ?
Answer:
1500 N/C
Explanation:
From the question,
Applying,
E = F/q.................. Equation 1
Where E = Electric Field intensity, F = Force experienced by the charge, q = Charge
Given: F = 6000 N, q = +4nC
Substitute these value into equation 1
E = 600/4
E = 6000/4
E = 1500 N/C
Hence, the electric field intensity is 1500 N/C.
Is sodium chloride a reactant
Answer:
yes it is a reactant
Which is used to zero a triple beam balance
A.
the pan
B.
a rider
C.
a beam
D.
the tare knob
The only major country that does not use the metric system
A.
France
B.
United States
C.
Russia
D.
England
Which statement is true of an alpha particle?
A. It is electromagnetic radiation, not a true particle.
B. It is an electron.
C. It is the largest decay particle
D. It is a particle that travels at the speed of light.
Answer:
Atoms are made up of various parts; the nucleus contains minute particles ... neutrons, and the atom's outer shell contains other particles called electrons. ... Physical Forms of Radiation; Radioactive Decay; Nuclear Fission; Ionizing Radiation ... of high-energy waves that can travel great distances at the speed of light and ...
Explanation:
The true statement of an alpha particle is it is an electron. The correct option is B.
What is an alpha particle?The alpha particle are composite particles which consists of two protons and two neutrons tightly bonded together. They are ejected from the inside the nucleus of heavy radioactive particles, also called alpha decay.
Atoms are made up electrons orbiting in outer shells, protons and neutrons in the nucleus. The radioactive particle emit highly ionized radioactive rays which ionize electrons emitting alpha particle.
Thus, the correct option is B.
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A decibel measures the _____________ of sound.
A.pitch
B,frequency
C.loudness
D.amplitude
PLEASE HELP! A 0.423 kg object carries a +11.5 uc
charge. It is 0.925 m from a -7.55 C
charge. What is the magnitude of the
object's acceleration?
(u stands for micro. Remember, magnitudes
are positive.)
[?] m/s2
Answer:
2.15 m/s²
Explanation:
We'll begin by calculating the force of attraction between two charges. This can be obtained as follow:
Charge of 1st object (q₁) = +11.5 μC = +11.5×10¯⁶ C
Charge of 2nd object (q₂) = –7.55 μC = –7.55×10¯⁶ C
Electrical constant (K) = 9×10⁹ Nm²/C²
Distance apart (r) = 0.925 m
Force (F) =?
F = Kq₁q₂ / r²
F = 9×10⁹ × 11.5×10¯⁶ × 7.55×10¯⁶/ 0.925²
F = 0.781425 / 0.855625
F = 0.91 N
Finally, we shall determine the acceleration of the object. This can be obtained as follow:
Mass of object (m) = 0.423 Kg
Force (F) = 0.91 N
Acceleration (a) =?
F = ma
0.91 = 0.423 × a
Divide both side by 0.423
a = 0.91 / 0.423
a = 2.15 m/s²
Thus, the magnitude of the object's acceleration is 2.15 m/s²
Answer:
2.15
Explanation:
Acellus
What is the color of lava at its hottest? Help asap
Answer:
the color the lava would be is orange
Explanation:
molten rock, known as magma, erupts through fissures in earths crust becoming lava. If that lava rises above 525 C (977 F) it glows red, with hotter lavas it becomes orange or even yellow.
hope this helps you.
In the 1500's Galileo experimented and discovered many things. One of his famous experiments allowed him to discover that blank when you drop them.
Answer:
In the 1500's Galileo experimented and discovered many things. One of his famous experiments allowed him to discover that all Objects fall the same rate Bolo when you drop them.
Explanation:
for mo
Seasons are more noticeable in places that are____from to the equator
Farther
Or
Closer
2.gravity and wind move water
True or false
It is for today pls help
A lightbulb has 25 W stamped on it. What does this mean?
Answer:
A lightbulb has 25 W stamped on it. What does this mean?:
These labels mean that each lightbulb has Its respective power delivered to It when It Is connected to a constant
Explanation:
Light travels at the same speed at all times. True False
Answer:
true hope this help :}
Explanation:
Kamal, Kamala, Krishna invert a sum of RS= 30,000 on a business in the ratio 2 : 3 : 5. Find the each of their investment.
Answer:
Explanation:
Kamal, Kamala, Krishna invert in the ratio 2 : 3 : 5.
As 2+3+5 =10, their respective share is 2/10, 3/10 and 5/10.
Sum of investment = 30000Rs
Kamal's investment = 30000 * 2/10 = 6,000 Rs
Kamala's investment = 30000 * 3/10 = 9,000 Rs
Krishna's investment = 30000 * 5/10 = 15,000 Rs
A longitudinal wave is a type of wave that transfers energy
Answer:
It transfers energy parallel to the direction of wave motion. A transverse wave..
Explanation:
Answer:
The answer is a Wave Motion
Explanation:
A longitudinal wave is a type of wave that transfers energy is called," Wave Motion".
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A boy walks towards a stationary plane mirror at a speed of 12ms^1 what is the relative speed of approach of the boy and his image? (a)zero (b)1.2ms^-1 (c) 2.4ms^-1 (d)1.44ms^-1
Answer:
a
Explanation:
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Which of the following best describes the circuit shown below?
A. Short
B. Combination
C. Series
D. Parallel
Answer:
The answer is C. Series.
Two waves, each with an amplitude of 0.5m are superimposed with constructive interference such that they are in phase. Describe the resultant amplitude
The resultant amplitude of the two waves is 1.0m
Interference occurs when two or more waves are superimposed over each other. These waves can either be destructive or constructive in nature. If the waves are superimposed with constructive interference such that they are in phase, the resultant amplitude will be the sum of the amplitude of both waves.Resultant amplitude = 0.5m + 0.5m
Resultant amplutude = 1.0m
Hence the resultant amplitude of the two waves is 1.0m
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