*Sorry for the bad quality picture!*
A frictionless pendulum with a mass of 0.4 kg and a length of 2.1 m starts at point A, at an angle 0 of 60°. As it swings downward, it passes through point B, which is 30 degrees from equilibrium. What is the kinetic energy of the pendulum at point B?
A) 3.9 J
B) 3.0 J
C) 1.1 J
D) 4.1 J
Answers
The conservation of mechanical energy allows finding the result for the speed of the pendulum when it is at 30º is:
The speed is: 3.88 m / s
The conservation of mechanical energy is a theorem of greater importance in physics and ordinary life, it states that if there is no friction force the total mechanistic energy remains constant at all points.
Mechanical energy is the sum of kinetic energy plus all potential energies. In the attachment we see a diagram of the pendulum's movement at the two points of interest.
They indicate that the pendulum is released from an initial angle of θ₁ = 60º, let's find the mechanical energy at that point.
Em₀ = U = m g h
Where the height is measured from the lowest point of the movement.
h = L - L cos tea1 = L (1 cos tea1)
The second point of interest occurs for θ₂ = 30º.
At this point part of the energy is indica and part gravitational potential.
[tex]Em_f[/tex] = K + U₂
[tex]Em_f[/tex] = ½ m v² + m g h ’
There is no friction in the system, therefore mechanical energy is conserved.
Em₀ = Em₀_f
mg L (1 - cos θ₁) = ½ m v² + m g L (1 - cos θ₂)
v² = 2g L (cos θ₂ - cos θ₁)
Let's calculate.
v² = 2 9.8 2.1 (cos 30 - cos 60)
v² = 41.16 0.366
v = 3.88 m / s
In conclusion using the conservation of mechanical energy we can find the result for the speed of the pendulum when it is at 30º is:
The speed is: 3.88 m / s
Learn more here: brainly.com/question/14688403
Answer:
3.0 J
Explanation:
Just took the test
Related Questions
Which of the following statements about migration is true?
a. Migration is always from one region to another.
b. Animals always migrate within a region.
c. Migration always negatively impacts an ecosystem.
d. Animals migrate for various reasons.
Answers
Answer:
A and D
b and C are false
Answer:
D. Animals migrate for various reasons.
Explanation:
Got it right on Edge 2023. : )
Question 2 of 10
You are riding a bicycle. If you apply a forward force of 125 N, and you and
the bicycle have a combined mass of 82 kg, what will be the forward
acceleration of the bicycle? (Assume there is no friction.)
A. 1.67 m/s2
B. 3.37 m/s2
C. 0.66 m/s2
D. 1.52 m/s2
O
Answers
Answer:
D - 1.52 m/s2
Explanation:
force: 125 N
Mass: 82 kg
you just divide the force by the mass which would be approximately 1.52
A student is asked to calculate the centripetal acceleration of a hummingbird that makes a complete circle in 0.43 seconds. If the circle has a radius of 0.25 m, what is
the correct setup for determining the centripetal acceleration of the hummingbird?
(3.65m/s)2/0.25m
(3.65m/s)2-0.43
O (0.435)2 / 25m
O (0.432.25m
Answers
The centripetal acceleration of the hummingbird is [tex]\frac{(3.65)^2}{0.25} = 53.29 \ m/s^2[/tex]
The given parameters;
time of motion of the hummingbird, t = 0.43 sradius of the circle, r = 0.25 mnumber of revolution of the hummingbird = 1 rev per 0.43 sThe angular speed of the hummingbird is calculated as follows;
[tex]\omega = \frac{1 \ rev}{0.43 \ s} \times \frac{2\pi \ rad}{1 \ rev} =14.61 \ rad/s[/tex]
The linear speed of the hummingbird is calculated as follows;
v = ωr
v = 14.61 x 0.25
v = 3.65 m/s
The centripetal acceleration of the hummingbird is calculated as follows;
[tex]a_c = \frac{v^2}{r} \\\\a_c = \frac{(3.65)^2}{0.25} \\\\a_c = 53.29\ m/s^2[/tex]
Thus, the centripetal acceleration of the hummingbird is [tex]\frac{(3.65)^2}{0.25} = 53.29 \ m/s^2[/tex]
Learn more here:https://brainly.com/question/11700262
identify impacts of air pollution
Answers
Answer:
Explanation:
High levels of air pollution can cause an increased risk of heart attack, wheezing, coughing, and breathing problems, and irritation of the eyes, nose, and throat. Air pollution can also cause worsening of existing heart problems, asthma, and other lung complications.
Ambient air pollution accounts for an estimated 4.2 million deaths per year due to stroke, heart disease, lung cancer and chronic respiratory diseases. Around 91% of the world's population lives in places where air quality levels exceed WHO limits.
Serious Effects of Pollution on Our Humans and Environment
Environment Degradation. The environment is the first casualty for the increase in pollution weather in air or water. ...
Human Health. ...
Global Warming. ...
Ozone Layer Depletion. ...
Infertile Land.
Please allow me to know if I helped you by clicking thank you, rating or brainly.
Thank you,
Miss Hawaii
Hope it can help you:)
Ex 2) A cannon ball is shot straight up into the air with an initial velocity of 25 m/s[Up).
What is the maximum height of the cannonball?
Answers
Explanation:
The final velocity at the cannon ball's maximum height is zero ([tex]v_y = 0[/tex]). We can use the equation
[tex]v_y^2 = 0 = v_{0y}^2 - 2gy_{max}[/tex]
[tex]\Rightarrow y_{max} = \dfrac{v_{0y}^2}{2g}[/tex]
[tex]y_{max} = \dfrac{(25\:\text{m/s})^2}{2(9.8\:\text{m/s}^2)}[/tex]
[tex]\:\:\:\:\:\:\:=31.9\:\text{m}[/tex]
Jasmine pushing her little brother on the swing the swing passes back-and-forth 14 times in 40 seconds what is the frequency of the motion and what is superior to the swing
Answers
Answer:
Explanation:
frequency f = 14 cycles/40 s
f = 0.35 cycles/s or
f = 0.35 Hz.
I suspect you are more concerned with the PERIOD of the swing rather than what is superior to it. (How would one even compare?)
T = 1/f = 1/0.35
T = 2.85714285...
T = 2.86 s
An object of mass 1.0 kg is at rest on a smooth inclined plane with height h, length 8 m,
and which makes an angle of 30° with the horizontal. The object is allowed to move, it
slides down and onto a rough horizontal surface. After traveling a distance of 4 m it hits a spring and travels 1.3 m more, all along the rough horizontal surface. The spring
constant is 26.5 N/m. What is the coefficient of kinetic friction for the horizontal surface?
Answers
The coefficient of kinetic friction for the rough horizontal surface is 0.66.
The given parameters;
mass of the object, m = 1 kglength of the inclined plane, L = 8 mangle of inclination of the plane, θ = 30⁰ distance traveled before hitting the spring, d₁ = 4 mdistance traveled after hitting the spring, d₂ = 1.3 mthe spring constant, k = 26.5 N/mApply work-energy theorem; the work done the force of friction is equal to the energy stored in the spring.
[tex]F_kd_1 = \frac{1}{2} kd_2^2\\\\\mu_kmg cos(\theta)d_1 = \frac{1}{2} kd_2^2\\\\\mu_k(1 \times 9.8 \times cos(30)\times 4) = \frac{1}{2} \times 26.5 \times (1.3)^2\\\\33.95\mu_k = 22.39\\\\\mu_k = \frac{22.39}{33.95} \\\\\mu_k = 0.66[/tex]
Thus, the coefficient of kinetic friction for the rough horizontal surface is 0.66.
Learn more here:https://brainly.com/question/10063455
A Wheatstone Bridge type circuit is shown (10marks) R1=20ohms, R2=10ohms, R3=8ohms, R4=5ohms, and R5=2ohms and also has 10V battery. Determine A. the p.d. between terminals B and D, and (5 marks) B. The value to which R4 must be adjusted in order to reduce the current through R3 to zero (balance the bridge). (5marks)
Answers
Answer:
Dunno
Explanation:
Dunno
A__________ shows how velocity changes over time
Answers
What provides the centripetal force for the moon's orbit around Earth?
Answers
Answer:
Gravitational attraction provides the centripetal force needed to keep planets in orbit around the Sun and all types of satellite in orbit around the Earth. This centripetal force is supplied by gravity. The Earth's gravity keeps the Moon orbiting us. Centripetal force is perpendicular to velocity and causes uniform circular motion. The gravitational attraction of the Sun is an inward force acting on Earth. This force produces the centripetal acceleration of the orbital motion. Centripetal forces are always directed toward the center of the circular path.
Explanation:
Answer: C.
the gravitational pull of the Sun
Explanation: plato :3
Hope this helps!
The gravitational force between two objects is 2700 N. What will be the gravitational force between the objects if the distance between them triples?
Answers
F = GMm/r^2
So F is proportional to 1/r^2
F2 = 2700 x ( 1 / 3^2 ) = 300N
What process makes this pattern on the ocean floor?
Answers
and the ocean floor
Bathymetry, the shape of the ocean floor, is largely a result of a process called plate tectonics.
please give me brainliest
Ex 3) A tennis player lobs the tennis ball up in the air during a serve at a rate 3 m/s.
How long will it take the tennis ball to reach its maximum height?
Answers
If a rock is thrown vertically upward from the surface of Mars with velocity of 20 m/s, its height (in meters) after t seconds is h = 20t − 1.86t2. (a) What is the velocity (in m/s) of the rock after 2 s? 12.56 Correct: Your answer is correct. m/s (b) What is the velocity (in m/s) of the rock when its height is 25 m on its way up? On its way down? (Round your answers to two decimal places.) up 8.07 Incorrect: Your answer is incorrect. m/s down -8.07 Incorrect: Your answer is incorrect. m/s
Answers
The velocity of the rock after 2s is 12.56 m/s.
The velocity of the rock at 25 m upwards is 14.68 m/s.
The velocity of the rock at 25 m downwards is -15.97 m/s.
The given parameters;
velocity of the rock, u = 20 m/sheight of the rock, h = 20t - 1.8t²The velocity of the rock after 2s is calculated as follows;
[tex]v = \frac{dh}{dt}= 20 -2(1.86)t \\\\v = 20 - 3.72t\\\\at \ t= 2 \ s \\\\v = 20 - 3.72(2) = 12.56 \ m/s[/tex]
The velocity of the rock when the height is 25 m:
h = 20t - 1.8t²
25 = 20t - 1.8t²
1.8t² - 20t + 25 = 0
solve for the time of motion "t" using quadratic formula
a = 1.8, b = -20, c = 25
[tex]t = \frac{-b \ \ +/- \ \ \sqrt{b^2 - 4ac} }{2a} \\\\t = \frac{-(-20) \ \ +/- \ \ \sqrt{(-20)^2 - 4(1.8\times 25)} }{2(1.8)}\\\\t = 9.67s, \ \ or \ 1.43 \ s[/tex]
The value of t that will give 25 m upwards using the motion model is 1.43 s;
h = 20(1.43) - 1.86(1.43)² = 25 m
The velocity of the rock at 25 m upwards (t = 1.43 s) is calculated as follows;
[tex]v = \frac{dh}{dt} = 20 -3.72t\\\\v = 20 - 3.72(1.43) \\\\v = 14.68 \ m/s[/tex]
The velocity of the rock at 25 m downwards (t = 9.67 s) is calculated as;
[tex]v = \frac{dh}{dt} = 20 - 3.72t\\\\v = 20 - 3.72(9.67)\\\\v = -15.97 \ m/s[/tex]
Learn more here:https://brainly.com/question/25233377
When adding vectors, what cannot change?
A. the vectors' length and direction
B. anything can change
C. only the vectors' length
D. only the vectors' direction
please help!!
Answers
Answer:
A
Explanation:
you cannot change the length and direction
number A is right I think
From what material did the moon form?How are eras and periods of the geologic time scale named?
Answers
Answer:
this
Explanation:
because of this its this ok
Answer: They are named for the places where geologists first described rocks or fossils from that time.
Explanation: ingenuity
Mr. Jones's prescription calls for 1.04 tablets per day. Based on this information, how many tablets should Mr. Jones take per day? a) 1.25 O b) 1.5 c) 1 O d) 2
Answers
Due to the fact that no one can consume .04 of a tablet, we can round down this answer to 1. This means that Mr. Jones should take C- 1 tablet per day.
I hope I've helped! :)
Mr. Jones's prescription calls for 1.04 tablets per day. Based on this information, he should take 1 tablet per day. The correct option is C.
What is prescription?The doctor suggests the medicine to be taken by the patient for the treatment of any disease or symptom is called as prescription.
Mr. Jones's prescription calls for 1.04 tablets per day. Based on this information, Mr. Jones must take 1 tablet per day.
No one can consume .04 of a tablet, we can round off 1.04 to 1. This means that Mr. Jones should take 1 tablet per day.
Thus, the correct option is C.
Learn more about prescription.
https://brainly.com/question/9537464
#SPJ2
Two horses are side by side on a carousel. Which has a greater tangential speed the one closer to the center or the one farther from the center? Explain your answer.
Answers
Answer:
The horse father from the center has a greater tangential speed. Although both horses complete one circle in the same time period, the one farther from the center covers a greater distance during that same period.
Explanation:
(a) Define the term ginning? (b) Name the simple device used for spinning?
Answers
A simple device used for spinning is a hand spindle also known as takli.
hope it helps
When the pushing force is increased to 88.2 N, the box just begins to move. What is the Friction Force if it is moving at a constant velocity? What is the coefficient of friction between the ground and box?
Answers
In order to calculate frictional force look below..
The formula given by
[tex]\\ \sf\longmapsto F_f=\mu N[/tex]
Or
[tex]\\ \sf\longmapsto F_f=\mu mg[/tex]
u is coefficient of friction
N is normal reaction.
9. Steradian is the angel which lies in:
a) One dimension
b) Two dimensions
Answers
Answer:
B
Explanation:
B
I DO NOT WANT LINKES OR …………..
Answers
Reasoning: a vacuum is empty space, therefore light can travel through, sound waves cannot travel through empty space!
How long does it take light from a camera to travel to the face of someone standing 7 meters away?
Answers
The time taken for the light to travel from the camera to someone standing 7 m away is 2.33×10¯⁸ s
Speed is simply defined as the distance travelled per unit time. Mathematically, it is expressed as:
Speed = distance / timeWith the above formula, we can obtain the time taken for the light to travel from the camera to someone standing 7 m away. This can be obtained as follow:
Distance = 7 m
Speed of light = 3×10⁸ m/s
Time =?Time = Distance / speed
Time = 7 / 3×10⁸
Time = 2.33×10¯⁸ sTherefore, the time taken for the light to travel from the camera to someone standing 7 m away is 2.33×10¯⁸ s
Learn more: https://brainly.com/question/14988345
cách đổi ev sang kj/mol
Answers
What element is chemically similar to carbon
Answers
nonmental
that should be the answer
A rock falls to the ground with a force of 300N and air resistance pushes back up on the rock with a
force of 45N. Which is true of the rock?
Answers
Answer:
what are the choices
Explanation:
don't worry i'll edit it
A stimulus that increses the occurance of a response is called
Answers
Answer:
reinforcing stimulus
Explanation:
Think its correct
Answer:
reinforcing stimulus
Explanation:
because it increases the occurence of a response
the electrical energy used to pump the water up to a mountain lake is 1.2 x 10 to the power 12 J only 6.2 x 10 to the power 11 J of electrical energy is generated when the water is released calculate the efficiency of this energy storage scheme
Answers
Answer:
Explanation:
ake is 1.2 x 10^12 J. Only 6.2 x 10^11 J of electrical energy is generated when the water is released. Calculate the efficiency of this energy
Why potential energy is remian constant when solid body is heated?
Answers
In a vacuum light travels at which speed?
Answers
Answer:
Light traveling through a vacuum moves at exactly 299,792,458 meters (983,571,056 feet) per second. That's about 186,282 miles per second
Explanation: