Answer:
Alkali metals are the chemical elements found in Group 1 of the periodic table. The alkali metals include: lithium, sodium, potassium, rubidium, cesium, and francium.
Explanation:
Answer:
alkali metals
Explanation:
To determine the height of a bridge above the water, a person drops a stone and measures the time it takes for it to hit the water. If the time is 2.3 s, what is the height of the bridge? Neglect air resistance.
a. 32 m
b. 52 m
c. 26 m
d. 14 m
e. 10 m
A stone dropped from a 26 m bridge, takes 2.3 s to reach the water.
A stone is dropped from a bridge and it experiences a uniformly accelerated rectilinear motion. It takes 2.3 s for the stone to reach the water.
We can calculate the height of the bridge, which is equal to the displacement of the stone, using the following kinematic equation.
[tex]s = ut + \frac{1}{2} a t^{2} = (0m/s)(2.3 s) + \frac{1}{2} (9.8m/s^{2} ) (2.3s)^{2} = 26 m[/tex]
where,
s: displacementu: initial speed (0 m/s)t: timea: acceleration due to gravity (9.8 m/s²)A stone dropped from a 26 m bridge, takes 2.3 s to reach the water.
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A vector has an x-component
of 6.15 m and a y-component
of -3.88 m.
Find the direction of the vector.
What do you put in the bowl first? milk or cereal?
Answer:
i put cereal first
Explanation:
cereal
3. Let the pen return to its vertical position and suddenly pull the thread.
Q4. What happened to the thread tied on the pen?
Answer:
The thread will experience a force on it .
Explanation:
When thread is tied to pen it will experience force. Because the pen is Abit heavy , there is a force that is applied to it which will cause it to elongate , after a while the thread will stretch, elongate and can later experience deformation. When it experience that, the thread can break after deformation and it has losses it elasticity.
what is science and examples with it
Answer:
science is the intellectual and practical activity encompassing the systematic study of the structure and behaviour of the physical and natural world through observation and experiment.
Explanation:
what of the average speed from 4s from 8s
A.0.5m/s
B.1m/s
C.2m/s
D.3m/s
E.9m
=====================================================
Explanation:
At 4 seconds, the distance is 8 meters. Note the point (4,8)
At 8 seconds, the distance is 10 meters. The point here is (8,10)
Find the slope of the line through (4,8) and (8,10)
m = (y2-y1)/(x2-x1)
m = (10-8)/(8-4)
m = 2/4
m = 1/2
m = 0.5
The average speed on this interval is 0.5 m/s
-----------------
Another way to look at it:
We've gone from 8 meters to 10 meters, so that's a change of y = 2 meters.
During this, the time has changed from 4 seconds to 8 seconds, which is a difference of x = 4 seconds.
The velocity is the rate of change of distance over time
velocity = (change in distance)/(change in time) = y/x = 2/4 = 0.5 m/s
Determine which wave carries the greater
amount of energy. explain
[04.05] An atom has an atomic number of 12 and a mass number of 25. How many neutrons does the atom have?
Answer: is 13
Explanation:
how long does it take a dollar bill that is 6 inches long to drop through its length (hint: Convert the length to meters and use a formula to find the time taken for the dollar to free fall through this length)
Answer:
3.4seconds
Explanation:
if a dollar was times for how long it would fall down to its length it would be 3.4 seconds
What are 3 parts of daltons atomic theory ?
A student weighs 530 N. The walk to the top of a 3m staircase. It takes them 5 seconds. How
much work did they do?
*
Answer:
W = 1590 J
Explanation:
We could use the formula of potential energy to find work as both have the same units,
W = mgh
since weight = mg so,
Work = weight x height
= 530 x 3
= 1590 J
Answer:
The work will be 1590 J
since the formula is W = F x D so I cancel the time
Explanation:
Given:
(Force) F = 530N
(Distance)D = 3m
Unknown:
W or Work
Formula and Solution:
W = F x D
W = (530N) (3m)
Final Answer:
W = 1 590 N·m or simplify as 1590 J
Is there work being done when kicking a soccer ball?
Answer:
Yes.
Explanation:
There is potential energy in your leg that once comes in contact with the ball turns into kinetic energy.
non examples of kinetic energy
Answer:
Anything that isn't moving
If the number of wavelengths that pass a point in a given time increases, what has increased?
A.frequency
B.amplitude
C.intensity
D.wavelength
What is the frequency of a wave that has a period of 5 seconds?
O A. 2 Hz
OB. 5 HZ
O C. 20 Hz
O D. 0.2 Hz
Answer: D
Explanation:
The frequency of a wave that has a period of 5 seconds is 0.2 Hz. Thus, the correct option is D.
What is Frequency?Frequency of a wave is the number of occurrences of a repeating event per unit of the time. Frequency is also occasionally referred to as the temporal frequency for clarity purpose, and it is distinct from that of angular frequency. Frequency is measured in SI units of hertz which is equal to one event per second of the time.
Frequency can be calculated as the number of waves that pass a fixed place in a given amount of time period. The frequency of a wave that has a period of 5 seconds is:
f = 1/T
where, f = frequency,
T = Time taken
f = 1/ 5
f = 0.2 hertz
Thus, the frequency of the wave is 0.2 hertz.
Therefore, the correct option is D.
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S1-CA-PHY41
The graph below represents the motion of a car during a 3.0 s time interval. What is the total displacement
of the object at the end of 3.0s
Answer:
The total displacement of the object is 20 m
Explanation:
Velocity vs Time Graph
It shows the behavior of the velocity as time increases. If the velocity increases, then the acceleration is positive, if the velocity decreases, the acceleration is negative, and if the velocity is constant, then the acceleration is zero.
The distance covered by the car can be calculated as the area behind the graph.
The total area can be calculated in two parts: One triangle from t=0 sec to t=2 sec, and one rectangle from t=2 sec to t=3 sec.
The area of a triangle is
A1= B*H/2, where B is the length of the base, and H is the length of the Height. The base is B=2 seconds, and the height is H = 10 m/s, thus:
A1= (2 sec)*(10 m/sec)/2=10 m
The area of a rectangle is
A2=W*L, where W is the width, L is the length. W=1 sec, L=10 m/s, thus:
A2=(1 sec)*(10 m/sec) = 10 m
Total displacement= 10 m + 10 m = 20 m
The total displacement of the object is 20 m
On an icy day, you worry about parking your car in your driveway, which has an incline of 12º. Your neighbor's driveway has an incline of 9.0º, and the driveway across the street is at 6.0º. The coefficient of static friction between tire rubber and ice is 0.15. Which driveway(s) will be safe to park in?
Answer:
Driveway across the street ([tex]\theta = 6^{\circ}[/tex]) is the only choice for a safe parking.
Explanation:
Let suppose that car is represented by a particle, then we proceed to construct its free body diagram and corresponding equations of equilibrium:
[tex]\Sigma F_{x'} = f - W\cdot \sin \theta = 0[/tex] (Eq. 1)
[tex]\Sigma F_{y'} = N-W\cdot \cos \theta = 0[/tex] (Eq. 2)
Where:
[tex]f[/tex] - Static friction force, measured in newtons.
[tex]N[/tex] - Normal force on the car from the ground, measured in newtons.
[tex]W[/tex] - Weight of the car, measured in newtons.
[tex]\theta[/tex] - Driveway inclination, measured in sexagesimal degrees.
By applying definitions of maximum static friction force and weight, we expand the system of equations presented above:
[tex]\mu_{s}\cdot N -m\cdot g\cdot \sin \theta = 0[/tex] (Eq. 1b)
[tex]N - m\cdot g \cdot \cos \theta = 0[/tex] (Eq. 2b)
Where:
[tex]\mu_{s}[/tex] - Static coefficient of friction, dimensionless.
[tex]m[/tex] - Mass of the car, measured in kilograms.
[tex]g[/tex] - Gravitational acceleration, measured in meters per square second.
Then, we substitute normal force and simplify the resulting expression:
[tex]\mu_{s}\cdot m\cdot g \cdot \cos \theta -m\cdot g \cdot \sin \theta = 0[/tex]
[tex]\mu_{s} = \tan \theta[/tex]
[tex]\theta = \tan^{-1}\mu_{s}[/tex] (Eq. 3)
Based on such result, we can conclude that if driveway inclination is greater than value reported, then car shall not be safe in case of parking. Our reference angle is: ([tex]\mu_{s} = 0.15[/tex])
[tex]\theta = \tan^{-1} 0.15[/tex]
[tex]\theta \approx 8.531^{\circ}[/tex]
By direct comparison, we find that driveway across the street ([tex]\theta = 6^{\circ}[/tex]) is the only choice for a safe parking.
where is the image located when an objectis placed 30cm from a convex lens with a focal length of 10cm?
Answer:
15 cm
Explanation:
using the thin lens formula for convex lens
[tex]\frac{1}{f} = \frac{1}{p} + \frac{1}{q}\\ \\where f = focal length \\ p = object distance \\ q = image distance\\[/tex]
so,
[tex]\frac{1}{q} = \frac{1}{f} - \frac{1}{p} \\\\\frac{1}{q} = \frac{1}{10} - \frac{1}{30} \\\frac{1}{q} = \frac{2}{30}\\\frac{1}{q} = \frac{1}{15cm}[/tex]
so,
q = 15 cm
The law of conservation of energy tells us
A. that energy can be transformed from one form to another
B. energy cannot be created or destroyed
C. the total amount of energy will remain the same
D. All of the above
Answer:
it is A
Explanation:
because energy can neither be created nor destroyed - only converted from one form of energy to another.
Remi travels 160 meters in 4 seconds. What was Remi's initial speed if her final velocity was 6.9 m/s?
Answer:
73.1 m/s
Explanation:
Given:
Δx = 160 m
v = 6.9 m/s
t = 4 s
Find: v₀
Δx = ½ (v + v₀) t
160 m = ½ (6.9 m/s + v₀) (4 s)
v₀ = 73.1 m/s
Explain the quantization of energy.
Answer:
The quantization of energy refers to the fact that at subatomic levels, energy is best thought of as occurring in discreet "packets" called photons. Like paper money, photons come in different denominations. ... Each photon contains a unique amount of discreet energy
What do x-direction and y-direction refer to when discussing an object's motion
Answer:
The x-direction and y-direction refer are used to refer to the location of an object as well as to the components of the motion of the object in a two dimensional space
Explanation:
In physics, in the analysis of the motion of an object in two dimensional space, the relative location of the object is specified using the measured distances in the x-direction from the y-axes and y-direction from the x-axes
In order to accurately specify the motion of the object, information regarding the component of the motion of the object in the x-direction and the component in the y-direction are required
What a noncrystalline solid
Which of the following statements is accurate when considering the role of cognition in shaping behavior? A. Cognition helps determine if a consequence is influential enough to control behavior. B. Cognition will most likely decrease the chance for classical conditioning to work. C. One’s cognitive processes are irrelevant when it comes to shaping behavior. D. One’s cognitive processes only work in shaping behavior when a particular consequence is desired. Please select the best answer from the choices provided A B C D
Answer: the answer is A.
Explanation:
brainliest please?
Answer:
A.
Cognition helps determine if a consequence is influential enough to control behavior.
Explanation:
This is right on edg. 2020
How much work is done to move a 1,000 N car 20 meters?
Answer:
The answer is 20,000 JExplanation:
The work done by an object can be found by using the formula
workdone = force × distanceFrom the question
force = 1,000 N
distance = 20 m
We have
workdone = 1000 × 20
We have the final answer as
20,000 JHope this helps you
Barbara plotted an elevation below sea level on a number line and labeled it A. She plotted Point B above 0, a distance that is exactly as far from 0 as Point A is. Explain what you know about Point B.
Answer:
Point A is the same distance below 0 as Point B is above 0.
Point B is a positive integer.
Since a number and its opposite are the same distance from 0 in opposite directions, Point B is the opposite of Point A.
Explanation:
Answer:
Sample Response: Because Point A is negative and the same distance below 0 on the number line as Point B is above it, Point B is both positive and the opposite of Point A.
Explanation:
I need this one fast!!!!
Nitrous oxide is the chemical name for "laughing gas." What are the names and the number of atoms in a molecule of
nitrous oxide, N2O?
1.one nitrogen atom and two oxygen atoms
2.two nitrogen atoms and one oxygen atom
3. one nitrogen atom and one oxygen atom
4. two nitrogen atoms and two oxygen atoms
Answer:
b
Explanation:
there are 2 nitrogen and 1 oxygen, you can tell by the little number after the letter. if there is no number, then it's just one atom
Answer:
B.
Explanation:
I got it right on my test.
How long does it take a dropped object to fall 45 meters?
Answer:
If we forget about drag for a second then any object will accelerate at 9.8 m/s/s. The distance traveled is (9.8 m/s)/2 * (x seconds)^2, so solving for 45 meters the no-air fall will take 3.06 seconds and reach 30 m/s or 108 kph or 67.1 mph
Explanation:
Describe at least three ways our understanding of the atom has changed.
Answer:
The first model of the atom was developed by JJ Thomson in 1904, who thought that atoms were composed purely of negatively charged electrons.
This theory was then disproved by Ernest Rutherford and the gold foil experiment in 1911, where Rutherford shot alpha particles at gold foil, and noticed that some went through and some bounced back, implying the existence of a positive nucleus.
In 1926, the Austrian physicist Erwin Schrödinger created a quantum mechanical model of the atom by combining the equations for the behavior of waves with the de Broglie equation to generate a mathematical model for the distribution of electrons in an atom.
Explanation:
A cannon is fired horizontally at 243 m/s off of a 62 meter tall, shear vertical cliff. How long will it take the
cannon ball to reach the ground?