Answer:
See explanation
Explanation:
a) Formula for the mass of the sample that remains after t years = N= Noe^-kt
Where;
N = mass at time t years
No = mass at time t= 0
k = decay constant
t = time taken
So,
N = 100e^-kt
b) First,
t1/2 = -ln(1/2)/k
t1/2 = 0.693/k
t1/2 = half life of radium-226 =1590 years
1590 = 0.693/k
k = 0.693/1590
k = 4.36 * 10^-4
So,
N= 100e^-(4.36 * 10^-4 * 1000)
N= 65 mg
c) From
N = 100e^-kt
40 = 100e^-(4.36 * 10^-4t)
40/100 = e^-(4.36 * 10^-4t)
0.4 = e^-(4.36 * 10^-4t)
ln(0.4) = ln(e^-(4.36 * 10^-4t))
-0.9163 = -4.36 * 10^-4t
t = 0.9163/4.36 * 10^-4
t = 2102 years
An object is moving with constant non-zero velocity. Which of thw following statements about it must be true
Answer:
The net force on the object is zero.
Explanation:
An object is moving with constant non-zero velocity. If velocity is constant, it means that the change in velocity is equal to 0. As a result, acceleration of the object is equal to 0. Net force is the product of mass and acceleration. Hence, the correct option is (d) "The net force on the object is zero".
A wave with a frequency of 5Hz travels a distance of 40mm in 2 seconds.What is the speed of the wave
Answer:
20mm per second
Explanation:
lol
A plastic ball in a liquid is acted upon by its weight and by a buoyant force. The weight of the ball is 4 N. The buoyant force has a magnitude of 5 N and acts vertically upward. When the ball is released from rest, what is it's acceleration and direction? [2 pts] for a Free Body Diagram correctly labeled.
Answer:
The acceleration is 2.448 meters per square second and is vertically upward.
Explanation:
The Free Body Diagram of the plastic ball in the liquid is presented in the image attached below. By Second Newton's Law, we know that forces acting on the plastic ball is:
[tex]\Sigma F = F - m\cdot g = m\cdot a[/tex] (1)
Where:
[tex]F[/tex] - Buoyant force, measured in newtons.
[tex]m[/tex] - Mass of the plastic ball, measured in kilograms.
[tex]g[/tex] - Gravitational acceleration, measured in meters per square second.
[tex]a[/tex] - Net acceleration, measured in meters per square second.
If we know that [tex]F = 5\,N[/tex], [tex]m = 0.408\,kg[/tex] and [tex]g = 9.807\,\frac{m}{s^{2}}[/tex], then the net acceleration of the plastic ball is:
[tex]a = \frac{F}{m} - g[/tex]
[tex]a= 2.448\,\frac{m}{s^{2}}[/tex]
The acceleration is 2.448 meters per square second and is vertically upward.
What does the Preamble to the Constitution set out as the goals for the government? Which branches of
government address each of the goals of the Preamble specifically?
Answer:
Six purposes of government: to form a more perfect union; establish justice; insure domestic tranquility; provide for the common defense; promote the general welfare; secure the blessings of liberty now and in the future.
Explanation:
Physics help, thank you guys so much!
Answer:
Δt = 5.85 s
Explanation:
For this exercise let's use Faraday's Law
emf = [tex]- \frac{d \phi}{dt}[/tex] - d fi / dt
[tex]\phi[/tex] = B. A
\phi = B A cos θ
The bold are vectors. It indicates that the area of the body is A = 0.046 m², the magnetic field B = 1.4 T, also iindicate that the normal to the area is parallel to the field, therefore the angle θ = 0 and cos 0 =1.
suppose a linear change of the magnetic field
emf = - A [tex]\frac{B_f - B_o}{ \Delta t}[/tex]
Dt = - A [tex]\frac{B_f - B_o}{emf}[/tex]
the final field before a fault is zero
let's calculate
Δt = - 0.046 (0- 1.4) / 0.011
Δt = 5.85 s
In 1976, a 53 kg helicopter was built in Denmark. Suppose this helicopter flew east with a speed of 60.0 m/s and the total momentum of the helicopter and pilot was 7,200 kg∙m/s to the east. What was the mass of the pilot?
Answer:
67 kg.
Explanation:
From the question,
Total momentum = (mass of the pilot+ mass of the helicopter)×velocity.
I = (m+M)v............................... Equation 1
Where I = Total momentum of the pilot and the helicopter, m = mass of the pilot, M = mass of the helicopter, v = velocity.
make m the subject of the equation
m = (I/v)-M.............................. Equation 2
Given: I = 7200 kg.m/s, v = 60 m/s, M = 53 kg.
Substitute these values into equation 2
m = (7200/60)-53
m = 120-53
m = 67 kg.
Hence the mass of the pilot is 67 kg
Help please :)
Ultraviolet waves are transmitted by ....... ?
Answer:
Sunlight is the greatest source of UV radiation. Man-made ultraviolet sources include several types of UV lamps, arc welding, and mercury vapour lamps.
Explanation:
Waves are ?
that can travel through matter.
Answer:
A wave can be thought of as a disturbance or oscillation that travels through space-time, accompanied by a transfer of energy. The direction a wave propagates is perpendicular to the direction it oscillates for transverse waves. A wave does not move mass in the direction of propagation; it transfers energy.
A ball is thrown straight up with an initial velocity of 128 ft/sec, so that its height (in feet) after t sec is given by s(t) = 128t-16t2. (a) What is the average velocity of the ball over the following time intervals? [3,4] ft/sec [3,3.5] ft/sec [3,3.1] ft/sec (b) What is the instantaneous velocity at time t = 3? ft/sec (c) What is the instantaneous velocity at time t = 6? ft/sec Is the ball rising or falling at this time? rising falling (d) When will the ball will hit the ground? t = sec
Answer:
one sec let me think
Explanation:
(a)The average velocity of the ball over the following time intervals will be [3,4] ft/sec.
(b)The instantaneous velocity at time t = 3 will be32 ft/sec.
(c)The instantaneous velocity at time t = 6 will be -64 ft/sec.
(d)The ball will hit the ground at 13.4 sec.
What is velocity?The change of displacement with respect to time is defined as the velocity. velocity is a vector quantity. it is a time-based component.
The given data in the question will be ,
u is the initial velocity by which ball thrown=128 ft/sec.
V₃ is the instantaneous velocity at time t=3 sec.
V₆ is the instantaneous velocity at time t=6 sec.
t is the time when ball hits the ground=?
(a) Given equation for the displacement
s(t) =128t-16t² (on differenting got the velocity )
v(t) = 128-32t
Time when velocity is zero will be
[tex]\rm{ t=\frac{128}{32}[/tex]
[tex]\rm{ t=4 sec[/tex]
If the velocity got in the equation is 128 and 32 ft /sec. it can be only when the average velocity is [3,4] ft/sec .
Hence the average velocity obtained from the problem will be [3,4] ft/sec
(b)
s(t) =128t-16t² (on differenting got the velocity )
v(t) = 128-32t
At time( t=3 sec)
v(3) = 128-32×3
v(3) =32 m/sec.
Hence the instantaneous velocity at time t = 3 will be32 ft/sec.
(c)
s(t) =128t-16t² (on differenting got the velocity )
v(t) = 128-32t
At time( t=6 sec)
v(6) = 128-32×6
v(6) = -64 m/sec.
Hence the instantaneous velocity at time t = 6 will be -64 ft/sec.
(d)
According to Newtons third equation of motion we got
v=u+gt
If the body returens from a certain height at max height its velocity must be zero; ( u=0)
[tex]\rm t=\frac{(v-u)}{g} \\\\\ \rm t=\frac{(128-0)}{9.81}\\\\\rm t=13.04 sec.[/tex]
Hence the ball will hit the ground at 13.4 sec.
To learn more about the velocity refer to the link ;
https://brainly.com/question/862972
The sun warms Earth through the process of _________
conduction
convection
insulation
radiation
Calculate wavelength of tube of length 15, 18, 20 cm.
Answer:In this lesson, the mathematical relationship between the tube's length, the speed of sound through air, and the ... Thus, the length of the air column is equal to one-half of the wavelength for the first harmonic. ... Determine the fundamental frequency (1st harmonic) of an open-end air column that has a length of 67.5 cm.
Explanation:
10POINTS!!
A satellite orbits Earth 350 km above Earth's surface. Calculate the free-fall acceleration at this altitude.
Answer:
8.82 m/s²
Explanation:
Formula for the free fall or gravitational acceleration is;
a = GM/r²
Where;
G is gravitational constant = 6.67 × 10^(-11) m³/kg.s²
M is mass of earth = 5.972 × 10^(24) kg
r is radius of earth = 6371 km
We are given that the satellite orbits Earth 350 km above Earth's surface.
Thus, new radius = 6371 + 350 = 6721 km = 6721000 m
Thus;
a = (6.67 × 10^(-11) × 5.972 × 10^(24))/(6721000²)
a = 8.82 m/s²
The course an object travels along is called DIRECTION.
A
TRUE
B
FALSE
DO NOT WRITE DOWN NONSENSE OR YOU WILL BE REPORTED!!!!!!!!
Explain what happens to the movement, energy and arrangement of particles during the process
of distillation.
Answer:
Distillation separates a liquid from a solution. For example, water can be separated from salty water by simple distillation. This method works because the water evaporates from the solution, but is then cooled and condensed into a separate container. The salt does not evaporate and so it stays behind.
cosmic Microwave Background radiation is one piece of supporting evidence for the Big Band Theory. Are these microwaves at the longer or shorter end of the spectrum?
are they long or short?
Answer:
it is long.
Explanation:
I know the answer but I don't know how to explain it
We intend to measure the open-loop gain (LaTeX: A_{open}A o p e n ) of an actual operational amplifier. The magnitude of LaTeX: A_{open}A o p e n is in the range of 106 V/V. However, the signal generator in measurement setup can supply minimal voltage of 1 mV, and the oscilloscope used at amplifier output can measure maximal voltage level of 10 V. Can you design a simple measurement setup using this signal generator and oscilloscope, and accurately measure the LaTeX: A_{open}A o p e n
Answer:
voltage divider, R₂ = 1000 R₁
measuring the output in the resistance R₁
Explanation:
Let's analyze the situation, in an op amp in open gain loop, the gain is maximum G = 10⁶ V / V
in this case the signal generator gives a minimum wave of 1 10⁻³ V, after passing through the amplified it becomes 10³ V which saturates the oscilloscope.
To solve this problem we must use a simple voltage divider, for this we use the fact that in a series circuit the voltage is the sum of the voltages of each element.
If we use two resistors whose relationship is
R₂ / R₁ = 10³
R₂ = 1000 R₁
When measuring the output in the resistance R₁ we have the desired divider, with a tolerance range, for the minimum output of the generator (1 10⁻³V) we have a reading of V = 1 V in the oscilloscope, for which we can use voltage up to 10V on the generator
Select the correct answer.
A pair of pliers is an example of a simple machine with two levers. Which part of the pliers is the fulcrum?
A. A
B. B
C. C
D. D
E. E
Answer:
There isnt enough in your question to answer the question bro, like we need a picture or something bro.
Explanation:
You don't have a image attached
An inclined plane consists of a 25 m length that raises an object 5 m above the ground. When pushing a 4500 N crate to the top of the ramp you exert 1000 N. What is the ideal Mechanical Advantage of this machine?
The IDEAL mechanical advantage of this ramp is (25m / 5m) = 5 .
But it's only giving you a real MA of (4500N/1000N) = 4.5 .
The friction between the crate and the surface of the ramp is robbing some of the work you do as you slide the crate up the ramp, which degrades the mechanical advantage.
What happens when a moving object experiences no net force?
Answer:
An object with no net forces acting on it which is initially at rest will remain at rest. If it is moving, it will continue to move in a straight line with constant velocity. Forces are "pushes" or "pulls" on the object, and forces, like velocity and acceleration are vector quantities.
student c precise or accurate darts
Answer:
i don't get it
Explanation:
What us a magnetic domain?
magnetic domain is a region within a magnetic material in which the magnetization is in a uniform direction. This means that the individual magnetic moments of the atoms are aligned with one another and they point in the same direction.
An alumium rod when measured with a steel scale both being at 25 degree celcius appears to be 1 meter long. If the scale is correct at 0 degree celcius, what is the true length of the rod at 25 degree celcius? What wull be the length of rod at 0 degree celcius?
determine the value of a and K when 0.51 is written is scientific nation
Answer:
The value 0.51
Explanation:
You pull with a force of 295 N on a rope that is attached to a block of mass 22 kg, and the block slides across the floor at a constant speed of 1.6 m/s. The rope makes an angle of 35 degrees with the horizontal. What is the net force on the block
Answer:
Fnet = 0
Explanation:
Since the block slides across the floor at constant speed, this means that it's not accelerated.According Newton's 2nd Law, if the acceleration is zero, the net force on the sliding mass must be zero.This means that there must be a friction force opposing to the horizontal component of the applied force, equal in magnitude to it:[tex]F_{appx} = F_{app} * cos \theta = 295 N * cos 35 = 242 N (1)[/tex]
In the vertical direction, the block is not accelerated either, so the sum of the normal force and the vertical component of the applied force, must be equal in magnitude to the force of gravity on the block:[tex]F_{appy} = F_{app} * cos \theta = 295 N * sin 35 = 169 N (2)[/tex]
⇒ 169 N + Fn = Fg = 216 N (3)
This means that there must be a normal force equal to the difference between Fappy and Fg, as follows:Fn = 216 N - 169 N = 47 N (4)At the bottom of the air track, the glider hits and stretches a rubber band, that causes the glider to change direction. When the rubber band is maximally stretched, the glider's kinetic energy is zero, because it is momentarily at rest. Since the glider is at the bottom of the air track, its (gravitational) potential energy is also zero. So the sum of the kinetic energy and gravitational potential energies is zero, yet energy is conserved. Where did the energy go?
Answer:
That energy is the elastic potential energy of the rubber band. At the bottom position, all the energy is being stored in the stretched rubber band, in the form of elastic potential energy.
Explanation:
When the glider reaches the bottom, its kinetic energy and potential energy become zero due to zero velocity and zero height, respectively. So, the sum of these energies will become zero. This will violate the law of conservation f energy. Hence, there must be a third type of energy that accounts for the conservation of the energy of the system at other configurations.
That energy is the elastic potential energy of the rubber band. At the bottom position, all the energy is being stored in the stretched rubber band, in the form of elastic potential energy.
what's the difference between kinetic energy, potential energy, and mechanical energy?
Answer:
potential energy is stationary, with stored energy to be released; kinetic energy is energy in motion, actively using energy for movement.
Explanation:
https://taraenergy.com/blog/potential-and-kinetic-energy-explained/#:~:text=The%20main%20difference%20between%20potential,actively%20using%20energy%20for%20movement.
(What is the weight of a 50 kg woman at the top of Jupiter's
atmosphere, where g = 24.8 N/kg? Give your answer in both
newtons and pounds.
Answer:
The correct answer is - 1240 newtons; 278.763 lbs.
Explanation:
An enormous thunderstorm covers Dallas-Ft. Worth. Your best friend Clark is a storm chaser and heads to the center of the storm to take some readings while you stay dry at home. While Clark is at the center of the storm, he sees and hears lightning strike a tree that is 190 m from where he is standing. You are 140 km from the tree. How long does it take for the sound to reach Clark
Answer:
407.61 seconds
Explanation:
Given that an enormous thunderstorm covers Dallas-Ft. Worth. Your best friend Clark is a storm chaser and heads to the center of the storm to take some readings while you stay dry at home. While Clark is at the center of the storm, he sees and hears lightning strike a tree that is 190 m from where he is standing. You are 140 km from the tree. How long does it take for the sound to reach Clark
Solution.
The distance between the Clark and you will be:
Distance = 140km - 190m
Distance = 140000 - 190
Distance = 139810 m
The radius of the earth is also considered but it will surely be insignificant as you subtracted the two distance values.
Using the formula
Speed = distance/time
Where
The speed of sound = 343 m/s
343 = 139810 / t
Make time the subject of formula
t = 139810 / 343
t = 407.61 s
Therefore, it will take 407.61 seconds for the sound to reach Clark
TRUE OR FLASE
12. During sleep the pituitary gland shuts down for the rest of the night.
13. When a person has a nightmare they wake up in a sweat and don't remember
the content of their dream.
Answer:
true for first and false for second
Explanation:
Someone pls help!! Right now :(