Answer:
The answer is 67.5 NExplanation:
The force acting on an object can be found by using the formula
Force = mass × accelerationFrom the question
mass = 45 kg
acceleration = 1.5 m/s²
We have
Force = 45 × 1.5
We have the final answer as
67.5 NHope this helps you
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?
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.
A box is being pushed across the floor at a constant velocity with an
applied force of 30N, what is the magnitude of the frictional force acting
on this box?
Answer:
Magnitude of frictional force = 30 N
Explanation:
According to the second Newton's law, the net force exerted by an external agent on an object of mass m is:
Fn=m.a
The net force is the vector addition of each individual force. If the sum of all the forces acting on an object is zero, then the acceleration is zero. That means the object moves at a constant speed or is at rest.
When an object is pushed across a horizontal rough surface, there are two forces acting in the direction of the motion: The applied force and the frictional force.
If the applied force is greater than the frictional force, then the object moves at a constant positive acceleration. If the frictional force is greater than the applied force, then the object won't move at all (if it was at rest) or will start a deaccelerated motion (braking).
Finally, if both forces are equal, the object will move at a constant speed or remains at rest. Since the box is moving at a constant speed, we can conclude the frictional force equals the applied force:
Magnitude of frictional force = 30 N
An object has a mass of 20,000kg and a density of 4000kg/m? What is its
volume?
How is ice more reflective than water??
Answer:
Because it has more texture and is solid. Its like glass
Explanation:
Answer:
Why is ice more reflective (has higher albedo) than liquid water? They're both the same substance (water). Is something quantum mechanical involved?
Explanation:
In fact ice is slightly less reflective than water. The reflectivity is related to the refractive index (in a rather complicated way) and the refractive index of ice is 1.31 while the refractive index of water is 1.33. The slightly lower refractive index of ice will cause a slightly lower reflectivity. In both cases the reflectivity is about 0.05 i.e. at an air/water or air/ice surface about 5% of the light is reflected.
The fastest human ever recorded was Usain Bolt at 43 km/h. If a white tail
deer can run 3 km in 3 minutes and 45 seconds, how many km/h faster would Usain Bolt need to run to catch a deer?
Please show work! Will mark brainliest!
A ship is travelling due east at
30 km/hr and boy runs across
the deck in a south east west
direction at 10 km/hr. Find the
veloocity of the boy relative to sea.
Answer:
The relative velocity of the boy with respect to the sea is 37.7 km/hr
Explanation:
Answer:
37.7 km/hr I'd the velocity
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?
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.
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
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!
Multidimensional development means that:
A. development is static.
B. development occurs in a positive flow.
C. development sometimes goes in only one direction.
D. development occurs in many different areas at the same time.
Answer:
option D
Explanation:
this is because it occurs in many different dimensions, including biological, cognitive and socioemotional. this is also the answer on apex.
Answer D would be correct for a p e x
The shortest path between two points is:
1) displacement
2) breadth
Answer:
the shortest path between two points is displacement..
Explanation:
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Which of the following statements about the technique of hypnotic regression is not true?
O Recovered memories are not reliable.
Courts often depend upon recovered memories.
O Memories may be planted by the hypnotist.
The process may create stress for the subject.
Answer:
B. is the correct answer just took the topic review.
Explanation:
Edge2020. Hope that this helps! Peace and Love
Courts often depend upon recovered memories is the wrong statement about the hypnotic regression.
What is hypnotic regression?Hypnotic regression is a contentious method because it can have a number of negative effects on the subjects who undergo it. For the beginners, the memories recovered through any regression can be doubtful and not trust-worthy. All the suggestions or leading questions from the hypnotist or other people of witnesses can affect the memory.
The previous lives memories will be found by the hypnotic technique as a past life regression. If they used to remember the past life by this method they have high chance of getting into the traumas.
Regression therapy mostly used to identify the cause of your current thoughts and reactions. Therapists who is using this techniques to access subconscious memories that are guiding your current behaviour.
Regression therapy is a method of treatment that could approach and focuses on resolving particular past events that are thought to be interfering or relatable with a person's current mental and emotional well-being.
Hence, Option B is the correct answer.
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Which is the best estimate for the width of a typical adult hand?
Answer:
About 4-5in
Explanation:
ln the constellation of Orion, you can see a group of stars and other objects that appear in the shape of a sword. Ln the middle of the sword, a bright "fuzzy star" appears. Astronomers looking at this object through telescopes refer to it as a "stellar nursery."What is another name for this object?
Answer:
Nebula
Explanation:
Given that in the constellation of Orion, you can see a group of stars and other objects that appear in the shape of a sword. Ln the middle of the sword, a bright "fuzzy star" appears. Astronomers looking at this object through telescopes refer to it as a "stellar nursery." Another name for this object is called NEBULA.
The space where new stars are forming anew is known as nebulae
Emma has a large piece of taffy (1.5 kg) that she wants to share with her friend Camila. However, Emma is having a hard time breaking the piece by herself. So, Emma grabs one end of the taffy while Camila grabs the other end. They both pull on the taffy in opposite directions: Emma pulls with 20 N and Camila with 23 N. Calculate the acceleration and give the direction of the acceleration.
Answer:
The acceleration is 2 m/s² in Camila's direction.
Explanation:
The acceleration can be found using the following equation:
[tex] \Sigma F = ma [/tex]
Where
F is the force
m is the mass of the taffy = 1.5 kg
a is the acceleration =?
Since Emma pulls one end of the taffy with 20 N and Camila pulls the other end with 23 N we have:
[tex] F_{C} - F_{E} = ma [/tex]
[tex]23 N - 20 N = 1.5 kg*a [/tex]
[tex] a = 2 m/s^{2} [/tex]
Hence, the acceleration is 2 m/s² in Camila's direction.
I hope it helps you!
– Un automóvil A viaja hacia el este a 80 Km/h, mientras que un segundo automóvil B viaja en la misma carretera a 70 Km/h. Determine la velocidad del automóvil B medida desde el automóvil A si: a) Viajan en sentido contrario acercándose uno al otro. B) Viajan en el mismo sentido.
Answer:
la respuesta esta abajo
Explanation:
La velocidad de un objeto A relativa a otro objeto B es la velocidad que el objeto A parecería tener para un observador que se mueve con B.
a) La velocidad relativa de dos cuerpos que se mueven en la dirección opuesta es la suma de su velocidad. Por lo tanto:
Velocidad relativa = 80 + 70 = 150 km / h
b) La velocidad relativa de dos cuerpos que se mueven en la misma dirección es la diferencia entre su velocidad. Por lo tanto:
Velocidad relativa = 80 - 70 = 10 km / h
true for false; "Acceleration is inversely proportional to mass."
Answer:
True
Explanation:
F = ma
We can rearrange to a = F/m
So if we increase a and F is constant, then m has to decrease because it is in the denominator.
5)
(64(6-2) =
A)
62
B)
8-9
C)
122
12-8
Answer:
B 8-9 because you had to subtract that number or simplify. then your answer is 8-9
If a car accelerates at a uniform 4.0 m/s, how long will it take to reach a speed of 36.0 m/s,
starting from rest?
Answer:
9s
Explanation:
v=u+at
36=0+4t
t=36-0/4
t=9s
What type of change is making water from H^2 and O^2 ?
A. chemical
B. physical
Answer: chemical
Explanation: To change from hydrogen to oxygen is a chemical change because if you change hydrogen to oxygen, it is still a chemical. The answer is chemical.
Answer:
chemical possibly
Explanation:
fact
How would changing the mass of a bat affect a player’s ability to swing the bat and adjust the path of the bat to hit a moving baseball or softball?
Answer:
Explanation:
The answer to that question is "both," though past players tend to have used heavier bats than do today's players. Baseball's "king of swat" Babe Ruth reportedly began his hitting career using a 54 ounce (1.5 kg) hickory bat, and is known to have used a 40oz bat in 1927 when he hit his 60 home runs.[1] Ty Cobb and Joe Di Maggio both played with 42oz bats and Rogers Hornsby used a 50oz piece of lumber. George Sisler, playing for the St. Louis Browns in the 1920's, made his bat heavier by hammering Victrola needles into the barrel of his bat.[2] In the 1950's Cincinnati Reds' Ted Kluszeski hammered tenpenny nails into his bat to make it heavier.
Other great hitters including Ted Williams, Rod Carew and Stan Musial used much lighter bats: 31-33oz.[1] Roger Maris used a 33oz bat to hit his 61 home runs in 1961. Many players have tried to make their bats lighter by drilling a hole in the barrel and filling it with cork. Detroit Tigers' Norm Cash admitted to using a corked bat in 1961 when he won the batting title with a .361 average (though he slumped to .243 the next year with the same corked bat).[2]
Kirkpatrick[3] reports that Roger Maris participated in a 1962 experiment in which he batted for distance with 5 different new bats whose weights varied from 33 to 47oz. He hit 5 long fly balls with each bat and the distances were measured and correlated to bat weight. The heavier bats, on average, resulted in further distance. However, Maris' preferred bat (which he used to break Babe Ruth's home run record) was the lightest of the set, even though it produced the shortest distance fly balls. Mark McGwire used a 35oz bat to hit his 70 home runs in 1998, and Barry Bonds used a 32oz bat to hit his 73 home runs in 2001. Most of today's major league players typically use 31-35oz bats.
Physicists have shown,[3,4] from a simple collision analysis, that the optimum bat weight is between 15 and 18oz. However, no professional batter uses a bat this light (in fact, you cannot make a wood bat this light). NCAA regulations[x] recently imposed a -3 rule (length in inches minus weigh in ounces cannot exceed 3) so that 34 inch bats must weigh 31oz. So far no such rule exists for Little League play, and -12 composite bats were introduced for the 2003 season. This brings us back to our original questions: which is better: heavier or lighter bats? So, what is the optimum bat weight, and what criteria influence this choice? Let's start by looking at the collision between ball and bat.
It’s really easy so plz help
Answer:false
Explanation:
In order to see inside atoms, they are broken apart with high speed
neutrons or electrons ?
Answer:
i think its electrons
Explanation:
Question 7 (2 points)
To draw conclusions in the scientific method means to decide if the Hypothesis is supported or not supported.
O True
O False
Answer:
Tire
Explanation:
Choose the law that BEST explains the example:
Throwing a ball with more force to increase acceleration is an example of Newton’s
first law?
2nd law
third law
none of these
How are velocity, wavelength, and frequency related
Answer:
The wave velocity and the wavelength are related to the wave's frequency and period by vw=λT or vw=fλ. The time for one complete wave cycle is the period T. The number of waves per unit time is the frequency ƒ. The wave frequency and the period are inversely related to one another.
Explanation:
A wave having a wavelength of 1.5 meters and amplitude of 3.0 meters
travels a distance of 15 meters in 3.0 seconds. Determine the frequency
and the period of the wave. *
Your answer
Answer:
velocity, v = 15m / 3.0s
= 5 ms^-1
velocity = wavelength × frequency
5 ms^-1 = 1.5m × f
f = 5 ms^-1 / 1.5 m
f = 3.33 Hz
f = 1/T
T = 1/f
= 1/ 3.33 Hz
= 0.3 s
frequency, f = 3.33 Hz
period, T = 0.3 s
What is the meaning of disgust?
Answer:
Disliking something
Explanation:
For an example : Ah you disgust me
Answer:
Strongly disproval of something (usual this something is gross)
"Profound dislike or annoyance caused by something sickening or offensive." - The Free Dictionary
Explanation:
Example: Her attitude filled me with disgust
Example 2: Your gross remarks disgust me.
All of the matter present at the beginning of a chemical reaction will still be present at the end of a chemical reaction, although possibly in a different form or substance. This is because of the...
A. Law of conversation of energy
B. Law Of Universal Gravitation
C. Law Of Conversation Of Mass
D. Ohms Law
Answer:
C. Law Of Conservation Of Mass
Explanation:
In this scenario, this would occur due and is explained by the Law of Conservation of Mass. This law basically states that the mass that exists during and after a chemical reaction must remain the same, assuming that the reaction is taking place in a closed environment where no loss of mass is occurring. This means that if the reaction is in a closed environment the mass should not change whatsoever even if it is not in the same form or substance as it was before the reaction occurred.
2. The dust usually sticks ton TV iscreen because dust
A. Falls on the TV screen
B.Particles are metallic conductors
C.Is attracted by magnets in the TV screen
D. Is attracted
by static charges on the TV scien.
Answer:c
Explanation:
What must be true for a hypothesis to become generally accepted by
scientists?
A. It must involve lots of complicated math.
B. It must have been tested by many scientists.
O O O O
C. It must be presented by a famous scientist.
D. It must be proven true by one experiment.
Answer:
B It must have been tested by many scientists.
Explanation:
trust me :)
For a hypothesis to become generally accepted by scientists, It must have been tested by many scientists. Hence option B is correct.
What is hypothesis ?A hypothesis is a theory put up to explain a phenomena. A hypothesis must be testable according to the scientific method for it to be considered a scientific hypothesis. Scientific hypotheses are often based on prior findings that cannot be adequately explained by the current body of knowledge. Despite the fact that the terms "hypothesis" and "theory" are sometimes used interchangeably, they are not the same thing. A working hypothesis is an acknowledged theory that has been tentatively supported and is put up for further investigation.
In formal logic, the term "hypothesis" is used to refer to the antecedent of a statement, or in the proposition, in a different sense.
Hence option B is correct.
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