Answer:
A
Explanation:
Remark
One of the handiest things to know in physics is something called dimensional analysis.
Look at the answers you are given. All of them are in N/m. That means 2 things.
No conversions are necessary
You divide Newtons / meters. You don't need to worry too much about a formula.
But if need a formula, it is F = k * x and you need k
x = 3.5 m
F = 20.0 N
k = F / x
k = 20.0/3.5
k = 5.71 to 3 places.
A waterfall is an example of what energy conversion?
Answer:
most common energy transformations is the transformation between potential energy and kinetic energy. In waterfalls such as Niagara Falls, potential energy is transformed to kinetic energy. The water at the top of the falls has gravitational potential energy. As the water plunges, its velocity increases.
Explanation:
Hope this helps you
( I got this from transformation and conservation article)
74Be decays with a half-life of about 53 d. It is produced in the upper atmosphere, and filters down onto the Earth's surface.
If a plant leaf is detected to have 350 decays/s of 74Be, how long do we have to wait for the decay rate to drop to 25 per second?
Answer:
201.8 days
Explanation:
The activity of a radioactive sample as a function of times is :
[tex]$R=R_0e^{\frac{0.693t}{T_{1/2}}}$[/tex]
Here, [tex]$R_0$[/tex] = the initial activity
[tex]$T_{1/2}$[/tex] = half life
t = elapsed time
Now rearranging the equation for time, t, we get:
[tex]$\frac{R}{R_0}=e^{-\frac{0.693t}{T_{1/2}}}$[/tex]
[tex]$\ln\left(\frac{R}{R_0}\right)=-\frac{0.693t}{T_{1/2}}$[/tex]
[tex]$t=\frac{-\ln\left(\frac{R}{R_0}\right)T_{1/2}}{0.693}$[/tex]
[tex]$t=\frac{-\ln\left(\frac{25}{350}\right)\times 53}{0.693}$[/tex]
= 201.8 days
Therefore, the required time is 201.8 days
With no friction, you can use the relationship between potential and kinetic energy to predict the speed of the car at the bottom of this hill from its starting height.
a. True
b. False
what is Archimedes principle?
Archimedes' principle states that a body immersed in a fluid is subjected to an upwards force equal to the weight of the displaced fluid. This is a first condition of equilibrium. We consider that the above force, called force of buoyancy, is located in the centre of the submerged hull that we call centre of buoyancy.
1. What kind of force is the force of gravity? (1 Point) contact force
non-contact force electromagnetic force imaginary force
Answer:
the answer is electromagnetic force because gravity is a force of attraction
If a car has a force of 900 N and has a mass of 650 kg. What would be the acceleration of the
car as it moves down the street?
which chareged particles contribute to electricity, magnetism, and light
Answer:
Explanation:charged particles create an electric force field. Moving charged particles create a magnetic force field. Accelerating charged particles produce changing electric and magnetic force fields which propagate as EM waves.
A 190 lb man riding a 30 lb bicycle rides up a hill 60 ft high in one minute. What is the horsepower developed during this time?
1. In order to change the speed of a wave, you must change something about the medium. T or F
2. Diffraction is the process in which waves spread out as they pass through an opening. T or F
3. The larger the opening a wave passes through, the more the wave will diffract. T or F
Answer:
1) False
As the frequency can be defined as the number of times wave formed per unit time or in other words the numbers of a combination of a crest and trough forms. So the frequncy of a sound wave depends upon the source producing sounds
2)False
Diffraction is the process in which a light wave bends when they pass through a specified medium such as water.
3)True
hope it helps
How much heat is required to heat 2 kg of water from 25°C to 40°C?
Answer:
126000 J
Explanation:
Applying,
Q = cm(t₂-t₁).................. Equation 1
Where Q = Amount of heat, c = specifc heat capacity of water, m = mass of water, t₁ = Initial temperature, t₂ = Final temperature.
From the question,
Given: m = 2 kg, t₁ = 25°C, t₂ = 40°C
Constant: c = 4200 J/kg.°C
Substitute these value into equation 1
Q = 2×4200(40-25)
Q = 2×4200×15
Q = 126000 J
3.6 Make innovative suggestions on how you could instill healthy environmental values
in communities.
You could hold rallies which attract a lot of people, they come and you discuss apon making the world a better place and how you want to shape the society.
A pole-vaulter is nearly motionless as he clears the bar, set 4.2 mm above the ground. He then falls onto a thick pad. The top of the pad is 80 cmcm above the ground, and it compresses by 50 cmcm as he comes to rest.
Required:
What is his acceleration as he comes to rest on the pad?
Answer:
-67.24 m/s²
Explanation:
From the given information:
Using the formula for Kinematic equation i,e [tex]v_y^2 -v_{0y}^2=2a_yd[/tex] to find the speed with which the pole-vaulter approaches the pad
where;
[tex]v_y =[/tex] the speed when the individual approaches the pad = ???
[tex]v_{oy}=[/tex] initial speed at the location of the bar = 0
[tex]a_y =[/tex] the individual acceleration which is also equivalent to acceleration due to gravity. = 9.8 m/s²
d = distance travelled
Thus;
d = 4.2m - 80 cm
d = 4.2 m - 0.8 m
d = 3.4 m
[tex]v_y^2 -(0)^2=2\times 9.8 \ m/s^2 \times 3.4 \ m[/tex]
[tex]v_y^2 =2\times 9.8 \ m/s^2 \times 3.4 \ m \\ \\ v_y ^2 = 66.64 \ m/s \\ \\ v_y = \sqrt{66.64 \ m/s} \\ \\ v_y = 8.2 \ m/s[/tex]
Thus, the initial speed of the pole-vaulter at the top of the pad = 8.2 m/s
Using the same above equation to determine the acceleration as the pole-vaulter approaches rest on the pad:
i.e
[tex]v_f^2 -v_{0}^2=2a_yd'[/tex]
[tex]0^2 -(-8.2\ m/s)^2=2a(0.5 \ m) \\ \\ a = - \dfrac{(8.2 \ m/s)^2}{2(0.5 \ m) } \\ \\ \mathbf{a = -67.24 \ m/s^2}[/tex]
A tension of 35.0N is applied downward on a 2.50kg mass. What is the acceleration of the mass?
A. -59.5 m/s2
B. -14.0 m/s2
C. -4.20 m/s2
D. -23.8 m/s2
Answer:
D. -23.8 m/s2
Explanation:
Answer:
[tex]\text{B. }-14.0\:\mathrm{m/s^2}[/tex]
Explanation:
From Newton's 2nd Law, we have [tex]\Sigma F=ma[/tex].
Substituting given values, we get:
[tex]-35.0=2.50a,\\a=\frac{-35.0}{2.50},\\a=\boxed{-14.0\:\mathrm{m/s^2}}[/tex]
*Note the negative sign simply implies that the mass is travelling downwards (direction).
please select all that would be categorized as vectors
Answer:
1. 10 ft/s² straight up
2. 4 Km north-west
3. 20 m/s South
Explanation:
To successfully categorize the quantities given above as vectors, we must understand what vector quantity is.
A vector quantity is a quantity that has both magnitude and direction.
Considering the question given above, the vector quantities are:
1. 10 ft/s² straight up
2. 4 Km north-west
3. 20 m/s South
The remaining quantities in the question are not considered as vectors because they only have magnitude but no direction. They are therefore referred to as scalar quantities.
Think about routine tasks that astronauts might need to do inside and outside a
spaceship. Choose several tasks, and describe the features the ship and spacesuits
should have to account for zero gravity as the astronaut completes the task. Use
Newton's laws of motion in your analysis..
from the NASA website, COPYRIGHT Jun 8, 2015
When two charged particles are moving toward each other, their velocities decrease until they eventually come to a
stop. What happens afterward? (1 point)
O They remain in the same place without moving.
O They accelerate toward each other.
O they bond and accelerate together.
O They accelerate in opposite directions.
When two charged particles are moving toward each other, they bond and accelerate together.
To find the correct statement among all the options, we need to know about electromagnetic force.
What is electromagnetic force?The force between any two dynamic charged particles is the electromagnetic force. It's a combination of electric force and magnetic force. What does happen, when two charged particles move towards each other?When two charged particles move towards each other, they combine with each other dur to the electromagnetic force. Then they are travelled together as a single particle along the direction of more acceleration.Thus, we can conclude that the option (C) is correct.
Learn more about electromagnetic force here:
brainly.com/question/13745767
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Science questions!! Please help!!
Post Assessment on Investigating the Immune System
please help!! Please choose the right answers!! Dont guess if you dont know the answers!!
Answer:
1. b
2. c
3. b
4. a
5. a
6. c
7. c
8. d
When the velocity of a body increase with time, it's acceleration is ---------
positive
negative
Answer:
Negative
Explanation:
At a playground a student runs at a speed of 5 m/s and jump onto a circular disk of radius 3/2 m that is free to rotate around a fixed vertical axle. The student jumps on the disk several times, and the angular speed after the student lands is measured each time. Which of the following angular speeds is not a reasonable value for the measured angular speed?
a. 0.5 rad/s
b. 1 rad/s
c. 2 rad/s
d. 3 rad/s
e. 4 rad/s
Answer:
e. 4 rad/s
Explanation:
The maximum amount of angular velocity that can be reached by the disk can be found using the following formula:
[tex]v = r\omega\\\\\omega = \frac{v}{r}[/tex]
where,
ω = maximum angular velocity = ?
v = linear speed = 5 m/s
r = radius of disc = 1.5 m
Therefore,
[tex]\omega = \frac{5\ m/s}{1.5\ m} \\\\\omega = 3.33\ rad/s[/tex]
Therefore, the angular speed can be lower than this value due to frictional losses, but it can not exceed this value in the given linear speed limit of 5 m/s.
Hence, the correct option is:
e. 4 rad/s
what is meant by measurementwhat are the three requirements for selecting a unit of a physical quantity
Answer:
Three requirements for selecting a unit are
1. The unit should be reproducible.
2. It should be possible to define the unit without ambiguity.
3. The value of the unit should not change with space and time.
An object is moving in a straight line at constant speed. A resultant torce begins to act upon
the object.
State the ways in which the force may change the motion of the object
Answer: The velocity magnitude or the velocity direction chages.
Explanation:
According to Newton's second law of motion, the acceleration of a system moved in same direction and is also directly proportional to the external force which acts on it while inversely proportional to the mass. The formula is: a = F/m
Based on the question, since the object obtains acceleration, then it can be infered that there will be changes in the velocity magnitude or the direction as a result of the motion.
The bob (weight) at the end of a pendulum has a mass of 0.3 kilograms. The bob is pulled to position B and allowed to swing. It goes all the way to position C and swings
back.
joules. If the maximum height of the bob is 0.45 meters when it swings back,
joules of energy was
The potential energy of the bob at position B is
transformed to thermal energy.
Use g = 9.8 m/s2 and PE = mxgxn.
Answer: The first box is 1.47
The second box is 1.323
Explanation:
The potential energy of the pendulum bob at position B is 1.323 J.
What is the potential energy of the box of the pendulum?Potential energy is the energy a body has by virtue of its position or state above the ground.
Potential energy = mass × acceleration due to gravity × heightThe mass of the bob = 0.3 kg
height above the ground = 0.45 m
acceleration due to gravity, g = 9.8 m/s^2
Potential energy = 0.3 × 0.45 × 9.8 = 1.323 J
Therefore, the potential energy of the pendulum bob at position B is 1.323 J.
Learn more about potential energy at: https://brainly.com/question/14427111
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Which situation is contrary to Newton’s first law of motion?
An object at rest begins to move when an external force is applied.
A moving object has a constant velocity under the influence of balanced forces.
An object at rest stays at rest as long as unbalanced forces act on it.
A moving object slows down when an external force is applied.
Answer:
An object at rest stays at rest as long as unbalanced forces act on it.
Explanation:
Inertia can be defined as the tendency of an object or a body to continue in its state of motion or remain at rest unless acted upon by an external force.
In physics, Sir Isaac Newton's First Law of Motion is known as Law of Inertia and it states that, an object or a physical body in motion will continue in its state of motion at continuous velocity (the same speed and direction) or, if at rest, will remain at rest unless acted upon by an external force.
The inertia of a physical object such as a truck is greatly dependent or influenced by its mass; the higher the quantity of matter in a truck, the greater will be its tendency to continuously remain at rest.
Hence, the situation which is contrary to Newton’s first law of motion is that, an object at rest stays at rest as long as unbalanced forces act on it.
According to Newton’s first law of motion, an object at rest stays at rest as long as unbalanced forces do not act on it.
Answer:
yes it right
Explanation:
cat
POSSIBLE POINTS: 4
A sound wave traveling through a solid material has a frequency of 5 hertz. The wavelength of the sound wave is 2 meters. What is the speed of sound in
the material?
50 m/s
1,000 m/s
.
25 m/s
10 m/s
17
18 19 20 21 22 23 24 25 26
19 20 21 2
Ne
12631
MAY
20
0
étv
Answer:
v = fy
speed is equal to frequency × wavelength
5 × 2
[tex]10m.s^{ - 1} [/tex]
If you make multiple measurements of your height, you are likely to find that the results vary by nearly half an inch in either direction due to measurement error and actual variations in height. You are slightly shorter in the evening, after gravity has compressed and reshaped your spine over the course of a day. One measurement of a man's height is 6 feet and 1 inch. Express his height in meters, using the appropriate number of significant figures.
Answer:
H = 1.85 m
Explanation:
First, we will convert the height completely into inches. 1 feet contains 12 inches in it. Therefore:
H = (6 feet)(12 inch/1 feet) + 1 inch
H = 73 inches
Now, we will convert this height from inches to meters. 1 inch is equivalent to 0.0254 m. Therefore:
H = (73 inches)(0.0254 m/1 inch)
H = 1.85 m
A fisherman notices that his boat is moving up and down periodically without any horizontal motion, owing to waves on the surface of the water. It takes a time of 2.10 s for the boat to travel from its highest point to its lowest, a total distance of 0.600 m . The fisherman sees that the wave crests are spaced a horizontal distance of 6.50 m apart.
Required:
a. How fast are the waves traveling?
b. What is the amplitude of each wave?
c. If the total vertical distance traveled by the boat were 0.30 m but the other data remained the same, how would the answers to parts (a) and (b) be affected?
Answer:
See Explanation
Explanation:
a) We know that;
v = λf
Where;
λ = wavelength of the wave
f = frequency of the wave
v = velocity of the wave
So;
T = 2 * 2.10 s = 4.2 s
Hence f = 1/4.2 s
f = 0.24 Hz
The wavelength = 6.5 m
Hence;
v = 6.5 m * 0.24 Hz
v = 1.56 m/s
b)The amplitude of the wave is;
A = 0.600 m/2 = 0.300 m
c) Since the wave speed does not depend on the amplitude of the wave then the answer in (a) above remains the same
Where d = 0.30 m
A = 0.30 m/2 = 0.15 m
HELP ASAP DUE IN 5MIN
1. When a skydiver jumps out of a plane, the force that converts PE to KE is ?
2. In a fair experiment, the things that can change, causing a change in the outcome are called?
3. For a test to produce strong evidence for a claim, how many variables must be tested at a time?
Lupus is a temporary disease that can be cured easily. True False
Answer:
falseeee
Explanation:
Description of a recent example of human trafficking that has displayed in your community
True or False: It would be easier to run on a planet with high gravity than one with less gravity.