Answer:
1 hours will be the best answer
The time taken for a sample to reduce by 98% is 33.86 hrs.
What is half life?Half life is the time taken by a radioactive material for the radioactivity of to reduce by half its original value.
The half life equation is:
A = A₀ (½)^(t / T)
where A is the final amount, A₀ is the initial amount, t is the amount of time, and T is the half life.
Given is the half-life of a radioisotope is 6.0 hours and activity of a sample to be reduced by 98%.
Final amount will be 1 - 0.98 = 0.02
Substituting the values, we get
0.02 = 1 (½)^(t / 6)
t = 6 {log(1/0.02)/log2}
t = 33.86 hrs
Thus, time taken is 33.86 hrs.
Learn more about half life.
https://brainly.com/question/24710827
#SPJ2
Jaune moves North 15 meters, South 5 meters, then North 8 meters. How far is Jaune DISPLACED?
Answer:
Displacement = 7 meters
Explanation:
Given that,
Jaune moves North 15 meters, South 5 meters, then North 8 meters. We need to find the displacement of Jaune.
The attached figure shows the motion of Jaune.
We know that, Displacement = final position - initial position
Initially, Jaune traveled 15 meters due North and finally, he travel 8 meters North.
Displcement = 15 m - 8 m
Displacement = 7 m
So, the displacement of Jaune is 7 meters.
HELP PLEASE !!!!!!! If a ball is accelerating down through the air with no horizontal motion, what must be true about the net forces acting on the ball? The gravitational force is greater than the drag. The net force on the ball is zero. The drag is greater than the gravitational force. The net force on the ball is directed upward.
physics
Answer:
A. The gravitational force is greater than the drag.
Explanation:
Remember that the second Newton's law says that:
F = m*A
Force equals mass times acceleration.
With this we will see that the correct option is:
"The gravitational force is greater than the drag."
We know that the ball is accelerating downwards, and there is no horizontal motion. Because the acceleration is downwards, we know that the net force must be downwards (for the second law).
Now, what must be true about the net forces acting on the ball? let's analyze each statement:
1) "The gravitational force is greater than the drag."
The gravitational force is what causes the objects to fall down to the ground, so if the ball is falling, this will always be true.
2) " The net force on the ball is zero."
We know that the ball is accelerating, thus the net force can not be zero, this is false.
3) "The drag is greater than the gravitational force. "
This is the opposite to the first option, this is false.
4) "The net force on the ball is directed upward."
The acceleration and the net force have the same direction, if the ball is accelerating downwards, then the net force is directed downwards. This is false.
Then the only true statement is the first one:
"The gravitational force is greater than the drag."
If you want to learn more, you can read:
https://brainly.com/question/19860811
What is the current in a circuit that has a power of 200 W and a resistance of 150 Ω
Answer:
Current = 1.15 AExplanation:
Since we are finding the current
Power in a circuit can be found by using the formula
[tex]P = I ^{2} R[/tex]Where
I is the current
R is the resistance
P is the power
From the question
Power = 200 W
Resistance = 150 Ω
Substitute the values into the above formula and solve for the current
That's
[tex]200 = 150{I}^{2} [/tex]Divide both sides by 150
We have
[tex] {I}^{2} = \frac{200}{150} \\ = \frac{4}{3} [/tex]Find the square root of both sides
We have
[tex]I = \sqrt{ \frac{4}{3} } [/tex]= 1.154700
We have the final answer as
Current = 1.15 A
Hope this helps you
A woman dropped a dime in a wishing well , she heard it 30 sec later ..Find velocity on impact while moving at 9.8 m/s 2
Answer:
The velocity at impact is 222.2 m/s
Explanation:
The given information are;
The time at which the woman heard the sound of the coin after dropping it into the wishing well = 30 seconds
The average speed of sound in air = 344 m/s
The time in which the dime travel = t₁
The time in which the sound travel = t₂
1/2 × 9.8 × t₁² = 344 × t₂
t₁ + t₂ = 30
4.9·t₁² = 344 × (30 - t₁)
4.9·t₁² + 344·t₁ - 10320 = 0
Which gives -344±
[tex]t_1 = \dfrac{-344\pm \sqrt{344^{2}-4\times 4.9 \times 10320}}{2\times 4.9}[/tex]
t₁ = 22.676 seconds or -92.9 seconds
Therefore the correct natural time is t₁ = 22.676 seconds
The velocity at impact, v = g×t₁ = 9.8 × 22.676 = 222.2 m/s
The velocity at impact= 222.2 m/s.
Two students make a model of a tree house they want to
The scale is 1:44. In the scale model, the tree house
has 2 windows.
How many windows should the real tree house have?
O A. 2
O B. 22
C. 4
D. 88
Answer:
A 2
Explanation:
Scaling deals with measurements.
for example, the question says, 1 : 44. Assuming we're using cm : m, this is inferring that, 1 centimeter on the model will represent 44 meters in real life. This means, the number of windows in the real tree will be carried down to the model, only the sizes would be reduced.
if a window in the real tree measures 44 meters, then it would be scaled down to be 1 centimeter on the model.
irrespective, models doesn't change the number of features, only the dimensions.
How much time does it take for a car with a speed of 85 m/s to drive a distance of 200 m? (1 point)
The car will take 2.35 seconds to drive a distance of 200 m.
What is speed?
Speed is a physical quantity that is a measure of the rate of change in the position of an object. It is the rate of change of distance with respect to time. Speed is a scalar quantity and is expressed as the magnitude of velocity, which is the rate and direction of motion of an object. Speed is measured in meters per second (m/s).
To find the time it takes for the car to drive a distance of 200 m with a speed of 85 m/s, we can use the formula:
time = distance / speed
Plugging in the values given, we get:
time = 200 m / 85 m/s
Simplifying this expression, we get:
time = 2.35 s
Therefore, it takes 2.35 seconds for the car to drive a distance of 200 m with a speed of 85 m/s.
To learn more about speed the link
https://brainly.com/question/28224010
#SPJ1
A box 5cm long, 4cm wide and 6cm high would have what volume? Show your work
Explanation:
volume= length×width×height
5cm×4cm×6cm = 20×6= 120cm³An internal combustion engine has an efficiency of 22.3%. This engine is used to deliver 6.25 x 104 J of work to drive the motion of the train. What is the total energy that needs to be put into the engine.
Answer:
Only about 12%–30% of the energy from the fuel you put in a conventional vehicle is used to move it down the road, depending on the drive cycle. The rest of the energy is lost to engine and driveline inefficiencies or used to power accessories. Therefore, the potential to improve fuel efficiency with advanced technologies is enormous.
If a man travels from 0m to 5m then back to -3m, all in four seconds, what is the mans displacement?
Answer:
-3 m
Explanation:
Displacement is the final position minus the initial position.
Δx = x − x₀
Δx = -3 m − 0 m
Δx = -3 m
if an object is moving with constant speed then its distance-time graph will be a straight line. (a)along time axis. (b)along distance axis (c)parallel to time axis (d)inclined to time axis
Answer: (d)inclined to time axis
Explanation:
For a moving object, the distance equation can be written as:
D = S*t
if S = 0, we will have a line parallel to the time axis.
if S = infinity we will have a line parallel to the distance axis.
Both options are discarded here, as S = ∞ is not possible, and S = 0 would mean that the object is not moving.
where D is the distance moved at the time t, t is the variable, and S is the speed of the object.
As S is constant, this equation defines a linear relationship.
The graph of this line will be a line that is not parallel either to the time axis nor the distance axis, this will be an inclined line that goes between them.
So the correct option is: (d)inclined to time axis
800 J of heat is needed to raise the temperature of 2 kg of iron by 1°C. What is the heat capacity of 3.6 kg of iron?
Answer: 1440 J/kg/degree Celsius
Explanation:
Heat capacity = thermal energy required / change in heat
A car traveling at 30 mis runs out of gas while traveling up a 10o slope. How far up the hill will the car coast before starting to roll back down
Answer:
5.21 milesExplanation:
The set up will be a right angle triangle (an inclined plane). The height of the inclined plane is the opposite side of the triangle while the distance traveled by the car along the slope will be the hypotenuse with angle of inclination of 10°.
Using the SOH trigonometry identity i.e sinθ = opposite/hypotenuse
sin 10° = opposite/30
opposite = 30sin10°
opposite = 5.21 miles
Hence the car must have traveled 5.21 miles up the hill before starting to roll back down.
A block of wood measures 12cm x 5cm x 10cm. Calculate the volume in (i) cm3 (ii) m3
Given:-
A block of wood measures 12cm x 5cm x 10cm.
To be calculated:-
Calculate the volume in (i) cm3 (ii) m3
Solution:-
Case 1 :
Volume of wood = 12cm x 5cm x 10cm
= 600 cm³
Case 2 :
12 cm = 12/100 = 0.12 m
5 cm = 5/100 = 0.05 m
10 cm = 10/100 = 0.01 m
Volume of wood = 0.12 × 0.05 × 0.01
= 0.00006 m³
What is your average velocity or speed if you travel 500 km in 3 hours
Answer:
166.6 km/h
Explanation:
500/3
=166.6
Two balls are released from the same height on the moon. They both reach the ground at the same time. Which statement is correct about the two balls
Answer:
same acceleration
Explanation:
What is the momentum of a 950kg car moving at 10.0m/s
Explanation:
Momentum = mass × velocity
p = mv
p = (950 kg) (10.0 m/s)
p = 9500 kgm/s
Which sport requires participants to wear safety equipment during competition?
Answer:
Football
Explanation:
Answer:
Hockey
Explanation:
The answer is hockey because in order to play hockey you have to have a lot of safety equipment because people play hockey by being very close to one another. Also, getting hurt during playing hockey without proper equipment can cause many damages to your body.
Hope this helps! :D
An atom of sodium-23 (Na-23) has a net charge of +1. Identify the number of protons, neutrons, and electrons in the atom. Then, explain how you determined the number of each type of particle
Answer:
11 protons, 12 neutrons, 10 electrons
Explanation:
Sodium has an atomic number of 11, so it has 11 protons.
The atomic mass is 23, so there are 23 − 11 = 12 neutrons.
The charge is +1, so there is 1 more proton than electrons, so there are 10 electrons.
4) A football player starts at the 40-yard line, and runs to the 25-yard line in 2 seconds.
a) What is their speed during that run?
b) What is their velocity?
I
c) If they kept running at that velocity for another 1.3 seconds, what would their
final position be?
Answer:
(a). Their speed during that run is 10 m/s.
(b). Their velocity is 6.86 m/s
(c). The final position is at 8.91 m.
Explanation:
Given that,
A football player starts at the 40-yard line, and runs to the 25-yard line in 2 seconds.
Suppose, the distance between 40 yard line and 25 yard line is 20 yard.
(a). We need to calculate their speed during that run
Using formula of speed
[tex]v=\dfrac{d}{t}[/tex]
Where. d = distance
t = time
Put the value into the formula
[tex]v=\dfrac{18.288}{2}[/tex]
[tex]v=10\ m/s[/tex]during that run
(b). We need to calculate their velocity
Using formula of speed
[tex]v=\dfrac{\Delta d}{\Delta t}[/tex]
Put the value into the formula
[tex]v=\dfrac{22.86-36.58}{2}[/tex]
[tex]v=-6.86\ m/s[/tex]
Negative sign shows the direction of motion.
(c). If they kept running at that velocity for another 1.3 seconds,
We need to calculate the final position
Using formula of position
[tex]d=vt[/tex]
Put the value into the formula
[tex]d=6.86\times1.3[/tex]
[tex]d=8.91\ m[/tex]
Hence, (a). Their speed during that run is 10 m/s.
(b). Their velocity is 6.86 m/s
(c). The final position is at 8.91 m.
5. a) A boy used a catapult to pluck a mango from a tree. State two forces involved in this activity?
Explanation:
Tensional force and gravitational force
As a 1850 kg car is traveling down a road, it experiences a force of friction of 121 N and a force of air resistance if 186N. If the engine is not applying any force, what is the acceleration of the car
Answer:
-0.166 m/s²
Explanation:
F = Ma
a = F/M = (121 N +186 N)/(1850 kg) = 0.166 m/s²
The acceleration of 0.166 m/s² is in the direction opposite to the direction of travel, so might be considered to be negative.
Answer:
-0.166 m/s²
As a 1850 kg car is traveling down a road, it experiences a force of friction of 121 N and a force of air resistance if 186N. If the engine is not applying any force, what is the acceleration of the car
The _______ is responsible for absorbing the most UV radiation.
a.
troposphere
b.
stratosphere
c.
mesosphere
d.
thermosphere
Please select the best answer from the choices provided
A
B
C
D
Answer:
The stratosphere is responsible for absorbing the most UV radiation.
Explanation:
Hope it will help you:)
The Stratosphere is responsible for absorbing the most UV radiation.
What is Stratosphere?The stratosphere is the second layer of the atmosphere as you go upward lying between the troposphere and the mesosphere.The external temperature of these planes decreases and then increases as they leave the stratosphere and return to the ground.This increase in temperature is a result of the ozone layer that is present in the stratosphere and absorbs the UV rays from the Sun, making an elevation in temperature. The stratosphere layer also called the ozonic atmospheric envelope, is important to human's life as it contains the ozone layer which absorbs the harmful ultraviolet radiations which emitted from the Sun and also it is convenient for flying of the planes .
Thus, the Stratosphere is responsible for absorbing the most UV radiation.
Hence, Option B is the correct answer.
Learn more about Stratosphere,
https://brainly.com/question/11928081
#SPJ2
HELP ME PLS!
Determine the presssure at the bottom of a container filled
with gasoline, if the height of the container is 200 cm long.
The gasoline's density is 680 kg/m3.
Explanation:
Pressure = Height * Density * acc. due to gravity
P = 2 * 680 * 9.8 = 13, 328 Pa
Answer:
13328pa
Explanation:
p = hgd
h = height = 200cm = 2m
g = 9.8m/s²
d = density = 680kg/m³
p = pressure
p = 2 x 9.8 x 680 = 13328pa
An electric iron of resistance 20Ω takes a current of 5A. Calculate the heat developed in 30seconds?
The amount of heat (H) produced is given by the joule’s law of heating as H= Vlt
Where,
Current, I = 5 A
Time, t = 30 s
Voltage, V = Current x Resistance = 5 x 20 = 100V
H= 100 x 5 x 30 = 1.5 x 10⁴ J.
Therefore, the amount of heat developed in the electric iron is 1.5 x 10⁴J.
Please mark me as a BRAINLIST
A voltage source is connected across two 1 kohm resistors in parallel. The current flowing through the voltage source is measure by a current meter as 2 mA. What is the voltage across each resistor
Answer:
1 Volt
Explanation:
The resistors have resistance R = 1 kΩ each = 1 x 10^3 Ω each
The current through the voltage source I= 2 mA = 2 x 10^-3 A
The resistors are in parallel, son the total resistance will be
[tex]\frac{1}{R_{T}}[/tex] = [tex]\frac{1}{R_{1}} + \frac{1}{R_{2}}[/tex]
[tex]\frac{1}{R_{T}}[/tex] = 1/1 kΩ + 1/1 kΩ
[tex]\frac{1}{R_{T}}[/tex] = 2/1 kΩ
[tex]R_{T}[/tex] = 1 kΩ ÷ 2 = 0.5 kΩ = 500 Ω
From V = IR
where V is the voltage
I is the current
R is the resistance
substituting, we have
V = 500 x 2 x 10^-3 = 1 V This is the voltage across each resistor
A light beam travels through a diamond (n=2.42) to pure water (n=1.33). The refracted ray will:
a) bend toward the normal
b) bend away from the normal
c) remain unchanged
d) bend toward the normal then away
Answer:
b) bend away from the normal
Explanation:
According to snell's law , if i be the angle of incidence and r be the angle of refraction
sin i / sin r = 1.33 / 2.42
sin i / sin r = .55
Hence sin r > sin i
r > i
In other words angle of refraction will be more than angle of incidence . So, the ray will bend away from the normal .
Tech A says that when a fuse has blown, it just has to be replaced, because it performed its job. Tech B says that when a fuse has blown, the circuit has to be diagnosed because the fuse was probably not the problem. Who is correct
Answer:
tech B
Explanation:
im assuming its ASE or CDX i got my ase certification
you should also always replace that fuse its there to stop a harmful amount of voltage to said thing like a starter or a a fan
What is the angular separation of two spectral lines of wavelengths 497 nm and 251 nm formed in the third order with a diffracting grating having 587 lines per millimeter
Answer:
34.8°
Explanation:
Given the following :
Number of lines (N) = 587mm
529mm to m = 587*1000 = 587000 per meter
d = 1 / N ; 1/587000 = 0.00000170357
Wavelength of light waves :
λ1 = 497nm = 497 × 10^-9 m
λ2 = 251nm = 251 × 10^-9 m
Angular position in 3rd order; m=3
For
λ1 ; dsinθ3 = 3λ1 ;
λ2 = dsinθ3 = 3λ2
Substituting values
dsinθ3 = 3λ1 =
0.00000189 * sinθ3 = 3 * 497 × 10^-9
θ3(1) = sin^-1(1491 * 10^-9 / 0.00000170357)
θ3(1) = sin^-1(0.8752208)
θ3(1) = 61.07°
λ2 = dsinθ3 = 3λ2
0.00000189 * sinθ3 = 3 * 251 × 10^-9
θ3(2) = sin^-1(753 * 10^-9 / 0.00000170357)
θ3(1) = sin^-1(0.4420129)
θ3(1) = 26.23°
Angular separation :
61.07° - 26.23° = 34.84°
34.8°
Imagina que compras una placa rectangular de metal de 2mm de alto, 10mm de ancho x 50mm de largo, y una masa de 0.02kg. El vendedor te dice que es de oro, pero para ver si de verdad es de oro, lo verificas calculando la densidad de la placa. ¿Cuál es el valor de la densidad de la placa? ¿Es de oro la placa rectangular?
Answer:
Densidad de la placa = 20 g/cm³.
La placa no es de oro.
Explanation:
Para encontrar la densidad de la placa rectangular primero debemos hallar su volumen:
[tex] V = 2 mm*10 mm*50 mm = 1000 mm^{3}*\frac{1 cm^{3}}{(10 mm)^{3}} = 1 cm^{3} [/tex]
Ahora, encontremos al densidad de la placa:
[tex] d = \frac{m}{V} = \frac{20 g}{1 cm^{3}} = 20 g/cm^{3} [/tex]
Dado que la densidad del oro es 19.32 g/cm³ y que la densidad de la placa rectangular calculada es 20 g/cm³, podemos decir que dicha placa no es de oro.
Espero que te sea de utilidad!
where would information on the chemical and physical properties of a specific chemical be located in a laboratory or in the workplace?
Answer:
Both
Explanation: