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
The idea is to get as much EMF produced from the sprinter running through it. If you were the Olympic coach on a year when there happens to be a global energy crisis, and medals were assigned based on how much EMF (or current) were produced by the sprinters, what 3 pieces of advice (one is quite obvious; the other two involve the fixed orientation of the baton and the maintained position of the baton within the circular solenoid cross-section) would you give your sprinters in order to win?
Answer:
the greater the speed, the greater the electromotive force
* The metal pole must be parallel to the field
* you must keep the ball of the field
Explanation:
To determine the advice to the runners, let's use the Farad equation to and
fem = -N [tex]\frac{ d \phi}{dt}[/tex] = -N [tex]\frac{ B A Cos \theta }{dt}[/tex]
how the runners are moving
fi = B l x
fem = -N B l v
therefore the advice we can give are:
* the greater the speed, the greater the electromotive force
* The metal pole must be parallel to the field
* you must keep the ball of the field
What is the relationship between CO2 levels and temperature?
What can you infer from this? (make a guess or assumption based on the data)
Approximately what year did the concentration of CO2 first exceed 300 ppm?
Answer:
I can infer that higher levels of CO2 result in warmer temperatures. The CO2 first exceeded 300 ppm in 1950.
Let me know if this helps!
a force is applied to the right to drag a sled to the right across Loosely packed snow with a rightward acceleration (considered friction forces)
Answer:
1.67 m/s²
Explanation:
Total force is;
ΣF = F_f + F_a
From the free body diagram attached, we see that the frictional force F_f is acting in a negative direction.
Thus;
ΣF = -15 + 30
ΣF = 15 N
Now, to get the acceleration, we will use the formula;
ΣF = ma
We are given m = 9 kg
Thus;
15 = 9a
a = 15/9
a = 1.67 m/s²
Which would be a good analogy of wave motion
Answer:
i believe it would be C
Explanation:
The chemical equation for the decomposition of potassium chlorate into potassium chloride and oxygen gas is
KCIO: |_ KCI + ___ 02
Which coefficients correctly balances the equation?
A) 4.4,3
B 3,3,2
C) 2,2,3
D
2, 1,3
E The equation is already balanced.
Answer:
Option C. 2, 2, 3
Explanation:
__KClO₃ —> __ KCl + __O₂
The above equation can be balance as illustrated below:
KClO₃ —> KCl + O₂
There are 2 atoms of O on the right side and 3 atoms on the left side. It can be balance by writing 2 before KClO₃ and 3 before O₂ as shown below:
2KClO₃ —> KCl + 3O₂
There are 2 atoms of K on the left side and 1 atom on the right side. It can be balance by writing 2 before KCl as shown below:
2KClO₃ —> 2KCl + 3O₂
Thus, the equation is balanced. The coefficients are: 2, 2, 3
a skydiver is falling down through the air but has not reach terminal velocity (not consistent velocity )(considered air resistance)
We are to find the acceleration.
Answer:
-9.2 m/s²
Explanation:
Total force is expressed as;
ΣF = F_d + F_g
We are given;
F_d = 50 N
Mass of skydiver = 78 kg
Thus, F_g = 78 × -9.8
g is negative since it is a free fall
Thus;
F_g = -764.4 N
ΣF = 50 - 764.4
ΣF = -714.4 N
Formula for acceleration is;
ΣF = ma
a = -714.4/78
a ≈ -9.2 m/s²
1. What does the Work-Energy Theorem state?
Work is equal to the change in kinetic energy
Work is equal to the change in momentum
Work is equal to the change in impulse
Work is equal to the change in position
The Work-Energy Theorem states that Work is equal to the change in kinetic energy, which is the first option . This theorem is an essential principle in physics and mechanics, so first option is correct.
Work (W) is a measure of the energy transferred to or from an object by a force acting on it. It is defined as the product of the force applied to the object and the displacement of the object in the direction of the force. When a force does positive work on an object, it transfers energy to the object, increasing its kinetic energy. Conversely, when a force does negative work on an object (opposite to its direction of motion), it takes energy away from the object, decreasing its kinetic energy. So, first option is correct.
Learn more about the work-energy theorem here.
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The rate at which work is done is known as which of the following?
A. Power,
B. Energy,
C. Momentum,
Answer:
A , power
Explanation:
Hope this is useful. Have a lovely rest of your day! God bless you.
(iii) Gareth cycles 5 laps at this constant spoed. Each lap is 500m.
Calculate the distance he travels.
I
Distance
Answer:
2500 m
Explanation:
Given that,
Each lap is 500 m
Gareth takes 5 laps.
We need to find distance traveled by Gareth. The distance covered by him is given by :
d = 5×500
d = 2500 m
Hence, he will travel 2500 m.
A truck of mass 1600 kg is traveling at 15 m/s. In order to avoid running over a squirrel in the middle of the road, the truck driver begins to brake. What must the braking force on the truck be if the truck comes to stop in 2 s? *
a)12000n
b) 8000n
c)7000n
d)6000n
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
An object which is dropped from a certain height has zero (0) initial velocity.
Answer:
0 m/s
Explanation:
if an object is dropped we know the initial velocity is zero when in free fall
Which of the following is an example of kinetic mechanical energy?
Immersive Reader
(2 Points)
A. A bike rolling down a hill
B. An elevated wrecking ball
C. A compressed spring
D. A loaded gun
E. A set mouse trap
Answer:
A
Explanation:
Kinetic energy must be moving. Potential energy has the ability to move but is not doing so at the moment.
A is likely the answer. But there's lots involved in that kind of motion.
B If the ball is elevated, it implies it is not moving yet. It has potential energy.
C Again, the spring is compressed. It will push something when it moves, but it is not moving yet.
D The load gun's bullet is not moving. It's still potential energy.
E. The mouse trap is set, but it is not moving. When the mouse eats the bait then it's potential energy will transform into kinetic energy.
A gun is fired on a day when the speed of sound is 335 m/s and an echo is heard 0.75 seconds later. How far away is the object that created the echo?
Answer:
v= 335 m/s
2∆t= 0.75 s
∆x= v.∆t → ∆x= 335×½×0.75 = 125.625 m
How does changing the frequency affect the sound that you hear?
Answer:
It leads to a higher pitch of sound which means the sound is louder.
Explanation:
When a sound is made, it will cause vibrations to occur.
The size of these vibrations are called amplitude while their speed is called frequency.
Now, the larger the vibrations implies that we will have high amplitude such that the sound is louder, whereas, the higher the frequency, the higher the pitch of sound and vice versa.
The larger the pitch, the louder the sound and vice versa.
Thus, increasing the frequency leads to higher pitch and ultimately louder sound.
Physics, calculating net force. Please work it out for me
Answer:
F = 2985.125 N
Explanation:
Given that,
The radius of curvature of the roller coaster, r = 8 m
Speed of Micheal, v = 17 m/s
Mass of body, m = 65 kg We need to find the net force acting on Micheal. Net force act the bottom of the circle is given by :
[tex]F=\dfrac{mv^2}{r}+mg\\\\F=m(\dfrac{v^2}{r}+g)\\\\=65(\dfrac{17^2}{8}+9.8)\\\\=2985.125\ N[/tex]
So, the net force is 2985.125 N.
The spacecraft was moved closer to the launcher by the same amount Wednesday as it was on Tuesday, and yet its speed went up much more. Claim 3 suggests that the magnetic force was much stronger on Wednesday than on Tuesday.
Consider the two subclaims for Claim 3 and answer the question below.
Claim 3.A: The magnetic force was much stronger on Wednesday because the magnet was stronger.
Claim 3.B: The magnetic force was much stronger on Wednesday because the magnetic force is stronger closer to the magnets.
Which claim do you think is more convincing, and why?
Answer:
The magnetic force was much stronger on Wednesday because the magnetic force is stronger closer to the magnets.
Explanation:
The magnetic force was much stronger on Wednesday than on Tuesday because the magnetic force is stronger closer to the magnets. Therefore claim 3B is more convincing.
What is magnetic force?Magnetic force can be described as a consequence of electromagnetic force which is caused due to the motion of charges. A moving charge surrounds itself with a magnetic field and the force that arises due to interacting magnetic fields.
The magnetic force between two moving charges is the effect exerted upon either charge by a magnetic field generated by the other. The magnetic force depends on the charge, the motion of each of the objects, and the separation between them.
The magnitude of the force is determined by the cross product of velocity and the magnetic field is equal to q.[v × B]. The resultant force can be described as perpendicular to the direction of the velocity and the magnetic field.
Therefore, the magnetic force was much stronger closer to the magnets.
Learn more about magnetic force, here:
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A boy kicks a football with a force of 20 N, the time the force acts for is 0.3s. Calculate the impulse on the ball.
Answer:
20 * .3 = 6N
Explanation:
The impulse on the ball kicked with a force of 20 N force 0.3 s is 6 Ns
From the question given above, the following data were obtained:
Force = 20 N
Time = 0.3 s
Impulse = ?The impulse on the ball can be obtained as follow:
[tex]impulse \: = force \: \times time \\ impulse \: = 20 \: \times \: 0.3 \\[/tex]
Impulse = 6 NsTherefore, the impulse on the ball is 6 Ns
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A centrifuge is a device used to separate materials by their masses. A sample in a centrifuge is rotated at high speeds along a circular path a distance of 10.0 cm from the center of the centrifuge. A centrifuge constantly accelerates a 1.00-gram sample from rest to a speed of 1,000 revolutions per minute in 1.00 seconds. Eventually, the sample reaches a speed 10.5 m/s. What is the magnitude and direction of the centripetal force acting on the sample
Answer:
F = 1.047 10⁻² N
Explanation:
Let's use kinematics to find the angular acceleration
w = w₀ + α t
as for rest w₀ = 0
w = α t
α = w / t
let's reduce the magnitudes to the SI system
w = 1000 rev / min (2π rad/ 1 rev) (1 min/ 60s) = 104.72 rad / s
m = 1.00 g (1 kg / 1000 g) = 1,000 10⁻³ kg
r = 10.0 cm (1 m / 100 cm) = 0.100 m
let's calculate
α = 104.72 / 1
α = 104.72 rad / s²
angular and linear variables are related
a = α r
a = 104.72 0.100
a = 10.47 m / s²
finally we substitute in Newton's second law
F = 1 10⁻³ 10.47
F = 1.047 10⁻² N
NEED HELP PLEASE
ASAP
SOMEONE!!!!!!!!
TRUE OR FALSE 3 QUESTIONS
OWA OWA :3
Answer:
8. True
9. true
10. false
Explanation:
Answer:
false
true
false
the galaxies are moving away from each other, not towards each other.
What is the earliest time at which the oscillator shown below is stationary?
Answer:
0.0s
Explanation:
I got it right in acellus
Answer: 0.0
Explanation:
When individuals improve their aerobic endurance, which body systems are affected?
When individuals improve their aerobic endurance, which body systems are affected?
Anwser: your heart and lungs
an austrain who lived in vienna who composed graetest music for waltz dance
What is the average kinetic energy of particles in a gas at a temperature of 245 Kelvins?
Answer:
2)
Explanation:
A vertical piston cylinder assembly contains 10.0kg of a saturated liquid-vapor water mixture with initial quality of 0.85 The water receives energy by heat transfer until the temperature reaches 320*C. The piston has a mass of 204kg and area of 0.005m2. Atmospheric pressure of 100kPa acts on the top side of the piston. Local gravitational acceleration is 9.81m/s2 Calculate the amount of heat transfer between the water and the surroundings in kJ. Enter a numeric value only. 6735.66
Answer:
Explanation:
From the given information:
At state 1:
Initial Quality [tex]= x_1 = 0.85[/tex]
mass = 10.0 kg
At state 2:
Temperature [tex]T_2 = 320^0[/tex]
mass of the piston [tex]m_p = 204 \ kg[/tex]
area of the piston [tex]A_p = 0.00 5 \ m^2[/tex]
Atmospheric pressure [tex]P_{atm}= 100 \ kPa = 100 \times 10^3 \ Pa[/tex]
Gravitational acceleration = 9.81 m/s²
[tex]\mathbf{P= P_1=P_2}[/tex], This is because there exists no restriction to the movement of the piston and provided the process is frictionless. So, the process 1-2 is regarded as constant.
To calculate the applying force balance over the piston by using force balance in the vertical direction:
[tex]\mathbf{P_{AP} = P_{atmA_p} + m_pg}[/tex]
∴
(100 × 10³)×0.005 + 204 × 9.31 = P × 0.05
P = 500248 Pa
P = 500.25 kPa
At state 1:
[tex]\mathbf{P_1 = P = 500.25 \ kPa}[/tex]
[tex]x_1 = 0.85[/tex]
Hence, this is a saturated mixture of liquid and vapor
Using the steam tables at 500.25 kPa
[tex]V_f = 1.093 \times 10^{-3} \ m^3/kg \\ \\ V_g = 0.375 \ m^3/kg \\ \\ U_f = 639.72 \ kJ/kg \\ \\ U_g = 2560.72 \ kJ/kg[/tex]
∴
Specific volume at state 1 is given as:
[tex]V_1 = [ V_f +x_1(v_g -v_f) ] \ at \ 500.25 \ kPa \\ \\ V_1 = 0.319 \ m^3/kg[/tex]
volume at state 1 is given by:
[tex]V_1 = mV_1 = 10 \times 0.319 \\ \\ V_1 = 3.19 \ m^3[/tex]
Similarly, the specific internal energy is:
[tex]U_1 = [U_f +x_1 (U_o-Uf)] \ at \ 500.25 \ kPa[/tex]
[tex]U_1 = 639.72 +0.82 (2560.72 -639.72)[/tex]
[tex]U_1 = 2272.57 \ kJ/kg[/tex]
At state 2:
[tex]P = P_1 = P_2 = 500.25 \ kPa \\ \\ T_2 = 320^0 \ C[/tex]
Using steam tables at P = 500.25 kPa and T = 320° C
[tex]V_2 = 0.541 \ m^3/kg \\ \\ U_2 = 2835.08 \ kJ/kg[/tex]
∴
[tex]V_2 = mV-2 = 10 \times V_2 = 5.41 \ m^3[/tex]
[tex]\text{Now; Applying the 1st law of thermodynamics to the system}[/tex]
[tex]_1Q_2 -_1W_2 = \Delta V =m(u_2-u_1) \\ \\ where;\ _1W_2 = P(V_2-V_1) \\ \\ _1Q_2 -P(V_2-V_1) = m(u_2-u_1) \\ \\ _1Q_2 - 500.25(5.91 -3.19) = 10( 2835.08 -2272.57) \\ \\ \mathbf{ _1Q_2 = 6735.66 \ kJ}[/tex]
A cart is pushed ahead for 3.5 s with a force of 360 N. Determine the change in momentum of the cart.
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:
In a thunderstorm at 32.0°C, Reginald sees a bolt of lightning and hears the thunderclap 2.00s later. How far from Reginald did the lightning strike? The speed of sound through air at 32.0°C is 350.2 m/s. Show your work.
PLEASE HELP, THANKS!
Answer:
d = 700.4 m
Explanation:
Given that,
The speed of sound through air at 32.0°C is 350.2 m/s.
Reginald sees a bolt of lightning and hears the thunderclap 2.00s later.
We need to find how far from Reginald did the lightning strike. Let the distance be d. So,
Speed = distance/time
d = vt
So,
d = 350.2× 2
d = 700.4 m
So, the required distance is 700.4 m.
what is the acceleration of an object that has a velocity of 25.0m/s and is moving in a circle of a radius of 10.0 m?
Answer:
[tex]a=62.5\ m/s^2[/tex]
Explanation:
Given that,
The velocity of the object, v = 25 m/s
Radius of the circle, r = 10 m
We need to find the acceleration of the object. The centripetal acceleration act on it. It is given by :
[tex]a=\dfrac{v^2}{r}\\\\a=\dfrac{(25)^2}{10}\\\\a=62.5\ m/s^2[/tex]
So, the acceleration of the object is equal to [tex]62.5\ m/s^2[/tex].
Which statement about oceans is incorrect?
A Evaporation occurs when water is warmed by the sun.
B Most evaporation and precipitation occur over the ocean.
C 97 percent of Earth's water is fresh water from the ocean.
D Water leaves the ocean by the process of evaporation.