Answers
1. A model can come in many shapes, sizes, and styles.
✅
2. Models can help scientists communicate their ideas, understand processes, and make predictions.
✅
3. Thomson's experiments with cathode ray tubes showed that all atoms contain tiny negatively charged subatomic particles or electrons.
✅
4. The plum pudding model has electrons surrounded by a volume of positive charge
✅
5. Electrons are kept in the orbit around the nucleus by the electromagnetic force.
IamSugarbee
Related Questions
A freshly prepared sample of radioactive isotope has an activity of 10 mCi. After 4 hours, its activity is 8 mCi. Find: (a) the decay constant and half-life T1/2; (b) How many atoms of the isotope were contained in the freshly prepared sample? (c) What is the sample's activity 30 hours after it is prepared?
Answers
Answer:
(a). The decay constant is [tex]1.55\times10^{-5}\ s^{-1}[/tex]
The half life is 11.3 hr.
(b). The value of N₀ is [tex]2.38\times10^{11}\ nuclei[/tex]
(c). The sample's activity is 1.87 mCi.
Explanation:
Given that,
Activity [tex]R_{0}=10\ mCi[/tex]
Time [tex]t_{1}=4\ hours[/tex]
Activity R= 8 mCi
(a). We need to calculate the decay constant
Using formula of activity
[tex]R=R_{0}e^{-\lambda t}[/tex]
[tex]\lambda=\dfrac{1}{t}ln(\dfrac{R_{0}}{R})[/tex]
Put the value into the formula
[tex]\lambda=\dfrac{1}{4\times3600}ln(\dfrac{10}{8})[/tex]
[tex]\lambda=0.0000154\ s^{-1}[/tex]
[tex]\lambda=1.55\times10^{-5}\ s^{-1}[/tex]
We need to calculate the half life
Using formula of half life
[tex]T_{\dfrac{1}{2}}=\dfrac{ln(2)}{\lambda}[/tex]
Put the value into the formula
[tex]T_{\dfrac{1}{2}}=\dfrac{ln(2)}{1.55\times10^{-5}}[/tex]
[tex]T_{\dfrac{1}{2}}=44.719\times10^{3}\ s[/tex]
[tex]T_{\dfrac{1}{2}}=11.3\ hr[/tex]
(b). We need to calculate the value of N₀
Using formula of [tex]N_{0}[/tex]
[tex]N_{0}=\dfrac{3.70\times10^{6}}{\lambda}[/tex]
Put the value into the formula
[tex]N_{0}=\dfrac{3.70\times10^{6}}{1.55\times10^{-5}}[/tex]
[tex]N_{0}=2.38\times10^{11}\ nuclei[/tex]
(c). We need to calculate the sample's activity
Using formula of activity
[tex]R=R_{0}e^{-\lambda\times t}[/tex]
Put the value intyo the formula
[tex]R=10e^{-(1.55\times10^{-5}\times30\times3600)}[/tex]
[tex]R=1.87\ mCi[/tex]
Hence, (a). The decay constant is [tex]1.55\times10^{-5}\ s^{-1}[/tex]
The half life is 11.3 hr.
(b). The value of N₀ is [tex]2.38\times10^{11}\ nuclei[/tex]
(c). The sample's activity is 1.87 mCi.
Find the resultant of an easterly force of 100 N and a southeast force of 80 N acting at 65 degrees to the 100 N force
Answers
Answer:
Resultant is 152 N at 28.5 degrees south to the 100 N force
Explanation:
Where are streams located?
Answers
Answer:
Larger seasonal streams are more common in dry areas. Rain-dependent streams (ephemeral) flow only after precipitation. Runoff from rainfall is the primary source of water for these streams. Like seasonal streams, they can be found anywhere but are most prevalent in arid areas.
Explanation:
A student fires a cannonball vertically upwards. The cannonball returns to the
ground after a 4.60s flight. Determine all unknowns and answer the following
questions. Neglect drag and the initial height and horizontal motion of the
cannonball. Use regular metric units (ie. meters).
How long did the cannonball rise?
unit
What was the cannonball's initial speed?
unit
What was the cannonball's maximum height?
unit
V
Answers
Answer:
(a). The distance is 207 m.
(b). The initial velocity is 45.0 m/s
(c). The maximum height is 103.3 m
Explanation:
Given that,
Time = 4.60 s
We need to calculate the initial velocity
Using equation of motion
[tex]v=u-gt[/tex]
Put the value into the formula
[tex]0=u-9.8\times4.60[/tex]
[tex]u=45.0\ m/s[/tex]
We need to calculate the distance
Using formula of distance
[tex]d=v\times t[/tex]
Put the value into the formula
[tex]d=45\times4.60[/tex]
[tex]d=207\ m[/tex]
We need to calculate the maximum height
Using equation of motion
[tex]v^2=u^2-2gh[/tex]
Put the value into the formula
[tex]0=(45.0)^2-2\times9.8\times h[/tex]
[tex]h=\dfrac{(45.0)^2}{2\times9.8}[/tex]
[tex]h=103.3\ m[/tex]
Hence, (a). The distance is 207 m.
(b). The initial velocity is 45.0 m/s
(c). The maximum height is 103.3 m
A water skier is towing by motorboat at a constant velocity of magnitude 15 km /h. The boat speed up, and after a short interval the skier is towed at a new constant velocity of magnitude 20 km/h. What is the net force on the skier when she is moving at 15 km/h? And at 20 km/h?
Answers
Answer:
The skier is experimenting a net force of 0 newtons in both cases. ([tex]v_{1} = 15\,\frac{km}{h}[/tex], [tex]v_{2} = 20\,\frac{km}{h}[/tex])
Explanation:
According to Newton's First Law, an object is in equilibrium when it is either at rest or moving at constant velocity, which means that net force is equal to 0 newtons.
Therefore, the skier is experimenting a net force of 0 newtons in both cases.
3. A person who is initially stationary is eventually walking
at a speed of 1.5 m/s after an acceleration of 0.5 m/s?,
calculate the distance it takes them to reach this speed.
4. A lorry pulls forward after initially being stationary, it
takes the lorry 40 m to reach a speed of 8 m/s, calculate the
lorry's acceleration.
7. A person begins moving after initially being stationary, the person
accelerates at 0.5m/s2 over a distance of 9m what is their final speed
Answers
Explanation:
3. A person who is initially stationary is eventually walking
at a speed of 1.5 m/s after an acceleration of 0.5 m/s?,
calculate the distance it takes them to reach this speed.
Given parameters:
Initial velocity = 0m/s
Final velocity = 1.5m/s
Acceleration = 0.5m/s
Unknown:
Distance = ?
Solution:
To solve this problem, we apply the relevant motion equation;
V² = U² + 2aS
where V is the final velocity
U is the initial velocity
a is the acceleration
S is the distance
Input the parameters;
1.5² = 0 + 2 x 0.5 x S
2.25= S
The distance to reach this speed is 2.25m
4. A lorry pulls forward after initially being stationary, it
takes the lorry 40 m to reach a speed of 8 m/s, calculate the
lorry's acceleration.
Given parameters:
Initial velocity = 0m/s
Final velocity = 8m/s
Distance = 40m
Unknown:
Acceleration = ?
Solution:
V² = U² + 2aS
Input the parameters and solve;
8² = 0² + 2 x a x 40
64 = 80a
a = [tex]\frac{64}{80}[/tex] = 0.8m/s²
7. A person begins moving after initially being stationary, the person
accelerates at 0.5m/s2 over a distance of 9m what is their final speed
Given parameters:
Initial velocity = 0m/s
acceleration = 0.5m/s²
distance = 9m
Unknown:
Final velocity = ?
Solution:
V² = U² + 2aS
Input the parameters and solve;
V² = 0² + 3 x 0.5 x 9
V² = 13.5
V = 3.7m/s
At a race car driving event, a staff member notices that the skid marks left by the race car are 9.06 m long. The very experienced staff member knows that the deceleration of a car when skidding is -40.52 m/s2. What can the staff member estimate for the original speed of the race car if it came to a stop during the skid?
Answers
Answer:
27.1 m/s
Explanation:
Given that at a race car driving event, a staff member notices that the skid marks left by the race car are 9.06 m long. The very experienced staff member knows that the deceleration of a car when skidding is -40.52 m/s2.
Using third equation of motion,
V^2 = U^2 + 2aS
Since the car is decelerating, the final velocity V = 0
Substitute all the parameter into the equation above,
0 = U^2 - 2 * 40.52 * 9.06
U^2 = 734.22
U = [tex]\sqrt{734.22}[/tex]
U = 27.096
U = 27.1 m/s approximately
Therefore, the staff member can estimate for the original speed of the race car to be 27.1 m/s if it came to a stop during the skid
A rocket takes off from Earth. It travels 825km in 75 seconds. What is the
speed of the rocket?
0 1 km/s
11 km/s
O 1.1 km/s
O 111 km/s
Answers
Answer:
11 km/s
Explanation:
v=s/t
v=825km/75s
v=11km/s
A moving object with a decreasing velocity covers distance during
each new second than it covered in the previous second.
A.the same
B.more
C.less
Answers
Which event is an example of condensation?
A. Wet clothes are drying on a clothesline.
B. A mirror fogs up when someone takes a hot shower.
C. Water drips from an icicle on the edge of a roof.
O D. Rain turns to sleet as it nears the ground.
Answers
Answer:
the answer to your question is b a mirror fogs up when someone takes a hot shower.
The process of conversion of gaseous water to its liquid form is called condensation. The fogs formed on the mirror from the hot shower is an example of condensation.
What is condensation?Condensation is the process of cooling up of water vapor to liquid water. Water vapor condenses when it cools. Condensation can be best understood from the reason behind raining.
When water vaporizers from resources and cools from the sky, and the vapor condenses to form liquid droplets. Similarly we can observe water droplets in the window pane due to the similar effect.
The water vapor arises from the hot shower condenses in the atmosphere and forms the drops on the mirror. Therefore, the mirror fogs up by the hot shower is an example of condensation.
To find more on condensation, refer here:
https://brainly.com/question/15563071
#SPJ5
the solubility of sugar is 30 degree Celsius at 220 what does it mean
Answers
Answer:
So, that if you put 100 mL of 30 degree water in a beaker, you could add up to 220 grams of sugar and it would eventually dissolve. In other words, that mass of sugar should dissolve in 100 mL of water to make a solution that is just saturated.
The solubility of sugar is 30° C at 220. This means 220g of sugar is dissolved in 100g of solvent to make the saturated solution at 30° C. Solutions.
What is the solution?Most frequently, the solubility is represented in terms of mass per volume of water. Solubilities are frequently stated as g/100 mL, g/100 g, or g/L of water.
The ratio you provided is probably 1 g of sugar to 100 mL of water. In other words, if you put 100 mL of water at 30 degrees in a beaker, you could add up to 220 grams of sugar, and it would finally dissolve.
To generate a solution that is just saturated, the mass of sugar should dissolve in 100 mL of water.
Therefore, at 220 degrees, sugar dissolves at 30 degrees. This indicates that to create the saturated solution at 30° C, 220g of sugar must be dissolved in 100g of solvent.
To learn more about the solution, refer to the link:
https://brainly.com/question/23901809
#SPJ6
To get employees to work longer hours, employers often offer __________ in the form of extra pay.
A.
costs
B.
benefits
C.
incentives
D.
consequences
Answers
Answer:
C
Explanation:
I took the test
2
How is acceleration related to force when mass is constant, according to Newton's second law of motion?
A. The acceleration is directly proportional to the net force,
OB
The acceleration is inversely proportional to the net force.
C. The acceleration is inversely proportional to the square root of the net force.
OD
The acceleration is directly proportional to the square root of the net force.
Reset
Next Question
Answers
Answer:
A
Explanation:
The acceleration of an object is directly proportional to its net force.
[tex]a = \frac{f}{m} [/tex]
Answer:
Correct choice: A. The acceleration is directly proportional to the net force
Explanation:
Newton's Second Law of Motion
According to Newton's second law of motion, the acceleration of an object is directly proportional to the net force F and inversely proportional to the object's mass m:
[tex]\displaystyle a=\frac{F}{m}[/tex]
Correct choice: A. The acceleration is directly proportional to the net force
What is the molar mass of the molecule C8H18, crude oil?
Answers
Answer:
114.23 g/mol
Explanation:
What are the SI units for distance and time?
Answers
Answer:
distance is meters, time is seconds
Answer:
distance is meters(m)
time is seconds (s)
Explanation:
What is the name of the kind of stretch that involves stretching as far as you can and then holding for 10-30 seconds
Question 2 options:
PNF
ballistic
dynamic
static
Answers
Answer:
Static stretching.
Explanation:
It is static stretching because it is a form of stretching which u can do actively for a period of time and you hold position for about 30 to 60 seconds which allow the muscles and connective tissues to lengthen. It is done after work out with out movement in order to loosen up muscles so as to gain flexibility.
A force of 500 N acts for a time interval of 0.001 second on an object of mass 0.20 kg that was initially at rest. Calculate the final velocity of the object after the force acts
Answers
Answer:
100
Explanation:
The final velocity of the object after the force acts is 2.5 meters per second.
To calculate the final velocity of the object after the force acts, we can use Newton's second law of motion, which states that:
Force = Mass × Acceleration
We need to find the acceleration of the object first. Since the object was initially at rest, its initial velocity (u) is 0 m/s.
The force acting on the object is 500 N, and the mass of the object is 0.20 kg. We can rearrange the equation to find the acceleration (a):
Acceleration (a) = Force / Mass
a = 500 N / 0.20 kg
a = 2500 m/s²
Now, we can use the kinematic equation to find the final velocity (v) of the object:
Final velocity (v) = Initial velocity (u) + (Acceleration × Time)
The initial velocity (u) is 0 m/s (since the object was initially at rest), and the time interval (t) is 0.001 second.
Final velocity (v) = 0 m/s + (2500 m/s² × 0.001 s)
v = 0 m/s + 2.5 m/s
v = 2.5 m/s
Hence, the final velocity of the object after the force acts is 2.5 meters per second.
To know more about final velocity here
https://brainly.com/question/28608160
#SPJ2
In economics, _________ is the amount of a resource that firms and producers are willing and able to provide to the marketplace
Answers
sectors are the amount of resources
can we add 2 atoms together? 3? How do particles combine to form the variety of matter one observes?
Answers
Select the correct answer.
Type O negative blood is considered the universal red blood cell donor because it
OA.
Has all 3 types of antigens.
OB.
Has all 3 types of antibodies.
Lacks all 3 types of antigens.
OD
Lacks all 3 types of antibodies.
Answers
Answer:
The answer is C.) Lacks all 3 types of antigens.
1. According to Newton's third law of motion, how are action
and reaction forces related?
2. How is momentum conserved?
3. Suppose you and a friend, who has exactly twice your mass,
are on skates. You push away from your friend. How does the
force with which you push your friend compare to the force
with which your friend
pushes you? How do your
accelerations compare?
4. Thinking Critical be ly comparing and Contrasting
Which has more momentum, a 250-kg dolphin swimming
at 6 m/s, or a 450-kg manatee swimming at 2 m/s?
(need 1-4 answered ASAP)
Answers
Answer:
you couldn't do this on your own or search it up on google
a car travels at a speed of 50 m/s for 13 seconds. what is the distance that the car travels?
Answers
d = s x t
= 50m/s x 13 s
= 650 m
The answer is 650m. Let me know if I got wrong
Will was riding his bike when a dog ran out in front of him. He slammed on his brakes. During this quick stop, some of the mechanical energy (his motion) was changed into
A) heat energy.
B) light energy.
C) kinetic energy.
D) gravitational energy.
Answers
Answer:
A
Explanation:
big brain
During this quick stop, some of the mechanical energy (his motion) was changed into heat energy.
What is energy?Energy is the ability to do work. There are different types of energy such as Heat energy, light energy, kinetic energy, and gravitational energy.
Heat is the energy that moves from one body to another when temperatures are different. Heat passes from the hotter to the colder body when two bodies with differing temperatures are brought together.
The joule is a unit of energy that serves as the SI unit for heat (J). The calorie (cal), which is defined as "the amount of heat necessary to raise the temperature of one gram of water from 14.5 degrees Celsius to 15.5 degrees Celsius," is another common unit of heat measurement.
Therefore, During this quick stop, some of the mechanical energy (his motion) was changed into heat energy.
To learn more about heat energy, refer to the link:
https://brainly.com/question/20038450
#SPJ6
a tennis ball is thrown straight up with an initial velocity of 22.5 m/s how much total time is the ball in the air
Answers
Answer:
4.6s
Explanation:
v=u+at
0=22.5+(-9.8)t
-22.5=-9.8t
t=-22.5/-9.8
t=2.295 s
The total time will double
2.295×2=4.59s
=4.6s
7. Your teacher has mixed salt, pepper, and water. Describe a procedure that you could use to separate this mixture. Be sure to list all of the materials you would need, your set up, and your expected results.
Answers
Answer:
hope this could help you
protons are present in sodium atom.
a 11
b 10
C 12
d 9
Answers
11
Explanation:
There are 11 protons in a sodium atom
conversion
18230 mJ to kJ?
Answers
Answer:
0.01823
Explanation:
big brain
A moving car skids to a stop with the wheels locked across a level roadway. Of the forces listed, identify which act on the car.
Normal
Gravity
Applied
Friction
Tension
Air resistance
Answers
Answer:
Normal, Gravity, Friction, and Air Resistance.
Explanation:
When a moving car skid to stop and its wheels are locked across, then the following forces will be applied on the car:
Normal force: It will act counter to gravity that pushes an object against a surface and acts perpendicular to the contact surface.
Gravity: Gravity force acts in each and every object having mass and it can not be avoidable. So, the gravity force will also apply to the car and attract it to the earth's surface.
Friction: Friction is a force that acts opposite to the motion and stops or slows motion. Friction will be applied to the car that will oppose the motion of the car and stop it.
Air resistance: air resistance is defined as the forces exerted by air that acts opposite to the relative motion of an object. Air resistance will also be applied to the car when it will skid to stop as we are always surrounded by the air.
Hence, the correct answers are "Normal, Gravity, Friction, and Air Resistance."
A soccer player applies a force of 48.4 N to a soccer ball while kicking it. If the ball has
a mass of 0.44 kg, what is the acceleration of the soccer ball?
A. 27.3 m/s2
B. 21.3 m/s2
C. 110 m/s2
D. 104 m/s2
Answers
Answer:
C. 110 m/s2
Explanation:
Force = Mass x Acceleration
Since we have the force and the mass, we can rearrange this equation to solve for acceleration by dividing both sides by mass:
Force/Mass = (Mass x Acceleration)/Mass
Acceleration = Force/Mass
Now we just have to plug in our values and calculate!
Acceleration = 48.4/0.44
Acceleration = 110m/s/s
It is option C. 110 m/s2
Hope this helped!
Consider a buggy being pulled by a horse.
Which is correct?
1. The horse can pull the buggy forward only
if the horse weighs more than the buggy.
2. The force on the buggy is as strong as the
force on the horse. The horse is joined to the
Earth by flat hoofs, while the buggy is free to
roll on its round wheels.
3. The horse pulls before the buggy has time
to react so they move forward.
4. The horse pulls forward slightly harder
than the buggy pulls backward on the horse,
so they move forward.
Answers
Answer:
Option 2
Explanation:
Answer:B
Explanation:because she started of with no money and now she made her money up