Answer:56
Explanation: I did the test
: Một mặt phẳng vô hạn tích điện đều, mật độ σ = 4.10-9 C/cm2, đặt thẳng đứng trong không khí. Một quả cầu nhỏ có khối lượng 8 g, mang điện tích q = 10-8 C treo gần vào mặt phẳng, sao cho dây treo lúc đầu song song với mặt phẳng. Lấy g = 9,8m/s2. Khi cân bằng, dây treo quả cầu hợp với mặt phẳng 1 góc bằng bao nhiêu?
Answer:
The angle is 16 degree.
Explanation:
A uniformly charged infinite plane, density σ = 4.10-9 C/cm2, is placed vertically in air. A small ball of mass 8 g, with charge q = 10-8 C, hangs close to the plane, so that the string is initially parallel to the plane. Take g = 9.8m/s2 . In equilibrium, by what angle does the string hanging from the ball make an angle with the plane?
Surface charge density, σ = 4 x 10^-9 C/m^2
charge, q = 10^-8 C
mass, m = 0.008 kg
Let the tension is the string is T and the angle is A.
[tex]T sin A = q E....(1)\\\\T cos A = m g .... (2)\\\\Divie (1) by (2)\\\\tan A =\frac{q E}{m g}\\\\tan A = \frac{10^{-8}\times 4\times 10^{-5}}{2\times 8.85\times 10^{-12}\times 0.008\times9.8}\\\\tan A = 0.288\\\\A = 16 degree[/tex]
pahelp po ako.
1. Which of the following terms refers to energy in motion?
A. kinetic energy C. potential energy
B. light energy D. thermal energy
2. Which of the following is a type of energy gained due to its position?
A. kinetic energy C. gravitational potential energy
B. light energy D. thermal energy
3. How do you get the total mechanical energy of an object in a closed system?
A. Get the sum of the initial and final kinetic energy.
B. Get the sum of the initial and final potential energy.
C. Get the sum of the kinetic energy and the potential energy.
D. Get the difference between the kinetic energy and the potential energy.
4. Which of the following is the best set up to observe the conservation of mechanical energy?
A. A cart rolling down a wooden ramp.
B. A wooden block falling in a vacuum.
C. A volleyball falling from a tall building.
D. a paper plane being launched from a tower.
5. A big rock was dropped from the third floor of a building. What happens to the kinetic energy of the ball as it falls?
A. The rock’s kinetic energy increases.
B. The rock’s kinetic energy decreases.
C. The rock’s kinetic energy remains the same.
D. The rock’s kinetic energy cannot be identified.
6. A heavy metallic ball was rolled up on a frictionless ramp. What happens to the gravitational potential energy of the ball as it rolls up the ramp?
A. The ball’s gravitational potential energy increases.
B. The ball’s gravitational potential energy decreases.
C. The ball’s gravitational potential energy remains the same.
D. The ball’s gravitational potential energy cannot be identified.
7. A 2kg ball is elevated up a building, how much is its potential energy 10m from the ground?
A. 5J C. 98J
B. 20J D. 196J
For items 8 to 10, refer to the illustration below. A ball is dropped at point W and travels along a frictionless path to reach point Z.
8. At which point does the ball has greatest gravitational potential energy?
A. W C. Y
B. X D. Z
9. At which point does the ball has greatest kinetic energy?
A. W C. Y
B. X D. Z
10. What happens to the total mechanical energy of the ball as it travels from point W to point Z?
A. The total mechanical energy increases.
B. The total mechanical energy decreases.
C. The total mechanical energy remains the same.
D. The total mechanical energy cannot be determined.
For items 11 to 12, refer to the illustration below. A pendulum swings back and forth from its highest position to its lowest position and vice versa.
11. As a pendulum swings from its highest to lowest position, what happens to its gravitational potential energy and kinetic energy?
A. Both its GPE and KE increases.
B. Both its GPE and KE decreases.
C. Its GPE decreases but KE increases.
D. Its GPE increases but KE decreases.
12. What happens to the total mechanical energy of the bob as it swings back and forth if only force acting on it is the gravitational force?
A. The total mechanical energy increases.
B. The total mechanical energy decreases.
C. The total mechanical energy remains the same.
D. The total mechanical energy cannot be determined.
Four ball of masses 0.5 kg, 1 kg, 2 kg, and 5 kg were dropped simultaneously on top of a building with the height of 20 m. Ignoring the air resistance, the four balls reach the ground at the same time.
13. Which of the following balls has the greatest gravitational potential energy on top of the building?
A. The ball with the mass of 5 kg.
B. The ball with the mass of 2 kg.
C. The ball with the mass of 0.5 kg.
D. All the balls have the same potential energy.
14. Which of the following balls has the least kinetic energy on top of the building?
A. The ball with the mass of 5kg.
B. The ball with the mass of 1kg.
C. The ball with the mass of 0.5kg.
D. All the balls have the same kinetic energy.
15. Which of the following balls has the greatest total mechanical energy?
A. The ball with the mass of 2kg.
B. The ball with the mass of 1kg.
C. The ball with the mass of 0.5kg.
D. All the balls have the same total mechanical energy
what is the angular speed w of the system immediately after the collision in terms f the sstem parameters and I
Answer: hello some part of your question is missing attached below is the missing detail
answer :
wf = M( v cos∅ )D / I
Explanation:
The Angular speed wf of the system after collision in terms of the system parameters and I can be expressed as
considering angular momentum conservation
Li = Lf
M( v cos∅ ) D = ( ML^2 / 3 + mD^2 ) wf
where ; ( ML^2 / 3 + mD^2 ) = I ( Inertia )
In terms of system parameters and I
wf = M( v cos∅ )D / I
What is the net force on a remote controlled airplane if a force of 57.6N is applied West and a force of 95.7N is applied South?
Answer:
112 N at 239°
Explanation:
Applying,
Pythagoras theorem,
a² = b²+c².................. Equation 1
Where a = net force
From the question,
Given: b = 57.6 N, c = 95.7 N
Substitute into equation 1
a² = 57.6²+95.7²
a² = 3317.76+9158.49
a² = 12476.25
a = √12476.25
a = 111.7 N
a ≈ 112 N
Then the direction is given as
∅ = tan⁻¹(c/b)........... Equation 2
∅ = tan⁻¹(95.7/57.6)
∅ = tan⁻¹(1.66)
∅ = 58.9°
∅ ≈ 59°
Since the angle is in the third quadrant,
∅' = 59+180
∅ = 239°
Hence the right answer is
112 N at 239°
Why do scientists use science
Answer:
Firstly, science helps our understanding of the world around us. Everything we know about the universe, from how trees reproduce to what an atom is made up of, is the result of scientific research and experiment.
Scientists use the scientific method to collect measurable, experimental evidence in an experiment related to a term (often in the form of an if/then statement), the results aiming to support or differ a theory. In other words, scientific method helps scientists get accurate, repeatable results.
4. An object is thrown from from the ground upward with an initial speed of 3.75 m/s. How long will the object be in the air before it lands on the ground?
Answer:
Explanation:
There's an easy way to answer this and then an easier way. I'll do both since I'm not sure what you're doing this for: physics or calculus. Calculus is the easier way, btw.
Going with the physics version first, here's what we know:
a = -9.8 m/s/s
v₀ = 3.75 m/s
t = ??
That's not a whole lot...at least not enough to directly solve the problem. What we have to remember here is that at the max height of a parabolic path, the final velocity is 0. So we can add that to our info:
v = 0 m/s. Use the one-dimensional equation that utilizes all that info and allows us to solve for time:
v = v₀ +at and filling in:
0 = 3.75 + (-9.8)t and
-3.75 = -9.8t so
t = .38 seconds. This is how long it takes to get to its max height. Another thing we need to remember (which is why calculus is so much easier!) is that at the halfway point of a parabolic path (the max height), the object has traveled half the time it takes to make the whole trip. In other words, if .38 is how long it takes to go halfway, then 2(.38) is how long the whole trip takes:
2(.38) = .76 seconds. Now onto the calculus way:
The position function is
[tex]s(t)=-4.9t^2+3.75t[/tex] The first derivative of this is the velocity function and, knowing that when the velocity is 0, the time is halfway gone, we will find the velocity function and then set it equal to 0 and solve for t:
v(t) = -9.8t + 3.75 and
0 = -9.8t + 3.75 and
-3.75 = -9.8t so
t = ,38 and multiply that by 2 to find the time the whole trip took:
2(.38) = .76 seconds.
The most powerful empire between the 1500s and 1600s was the __________ Empire.
A.
Ottoman
B.
Mauryan
C.
Roman
D.
Persian
Answer:
A
Explanation:
Answer:
Ottoman
Explanation:
siri told me after I asked
In one of the classic nuclear physics experiments at the beginning of the 20th century, an alpha particle was accelerated toward a gold nucleus, and its path was substantially deflected by the Coulomb interaction. If the energy of the doubly charged alpha nucleus was 2.25 MeV, how close (in m) to the gold nucleus (79 protons) could it come before being deflected
Answer:
The answer is "[tex]1.01 \times 10^{-13}[/tex]"
Explanation:
Using the law of conservation for energy. Equating the kinetic energy to the potential energy.
[tex]KE=U=\frac{kqq'}{r}\\\\[/tex]
Calculating the closest distance:
[tex]\to r=\frac{kqq'}{KE}\\\\[/tex]
[tex]=\frac{k(2e)(79e)}{KE}\\\\=\frac{k(2)(79)e^2}{KE}\\\\=\frac{9.0\times 10^9 \ N \cdot \frac{m^2}{c}(2)(79)(1.6 \times10^{-19} \ C)^2}{(2.25\ meV) (\frac{1.6 \times 10^{-13} \ J}{1 \ MeV})}\\\\[/tex]
[tex]=\frac{9.0\times 10^9 \times 2\times 79\times 1.6 \times10^{-19}\times 1.6 \times10^{-19} }{(2.25 \times 1.6 \times 10^{-13}) }\\\\=\frac{3,640.32\times 10^{-29}}{3.6 \times 10^{-13} }\\\\=\frac{3,640.32}{3.6} \times 10^{-16}\\\\=1011.2 \times 10^{-16}\\\\=1.01 \times 10^{-13}[/tex]
Question 5 of 10
A 15 N force is applied to an object, which then accelerates at 5.0 m/s2. What
is the mass of the object?
A. 10 kg
B. 20 kg
C. 75 kg
D. 3.0 kg
Hi there!
[tex]\large\boxed{D. \text{ } 3.0 kg}}[/tex]
Use the following equation to solve:
F = ma, where:
F = Force (N)
m = mass (kg)
a = acceleration (m/s²)
Thus:
15 = 5m
15/5 = m
mass = 3 kg
What is the current flowing through the circuit shown? (V= 110 V, R, = 200, R2 = 300, R3 = 10 0) (Ohm's law: V = IR)
A. 1.8 A
B. 20 A
C. 0.05 A
D. 0.55 A
Answer:
A
Explanation:
The first thing you have to do is go back and list the resistances correctly. R1 = 20 R2 = 30 and R3 = 10.
Leave the units off if you can't make an omega.
The resistance of a series circuit (that's what this is) is r1 + r2 + r3 = 10 + 20 + 30 = 60 ohms
Now use ohms law.
R = 60 ohms
V = 110 volts.
I = V / R
I = 110/60
I = 1.833 to the nearest 1/10 = 1.8
what is acceleration
[tex]\boxed{\large{\bold{\blue{ANSWER~:) }}}}[/tex]
[tex]\sf What \: is \: acceleration? \\ \\ \sf The \: rate \: of \: change \: of \: velocity \: of \: an \\ \sf object \: with \: respect \: to \: time \\ \sf is \: known \: as \: acceleration. [/tex]
Can somebody help me understand this
Do the data for the first part of the experiment support or
refute the first hypothesis? Be sure to explain your
answer and include how the variables changed in the
first part of the experiment.
Mechanical equivalent of heat
Answer:
Sample Response: The data for the first part of the experiment support the first hypothesis. As the height of the cylinder increased, the temperature of the water increased. At a greater height, the cylinder has more gravitational potential energy. This gravitational potential energy was completely converted to thermal energy, which increased the temperature of the water.
Explanation:
this the sample response from ED mechanical equivalent of heat lab.
Answer:
Sample response:
Explanation:
The data for the first part of the experiment support the first hypothesis. As the height of the cylinder increased, the temperature of the water increased. At a greater height, the cylinder has more gravitational potential energy. This gravitational potential energy was completely converted to thermal energy, which increased the temperature of the water.
Sonny took 16 seconds to finish a 100-m race. What was
Sonny's average speed in the race
Speed = Distance/Time
=> Speed = 100m/16s
=> Speed = 6.25m/s
=> Speed = 6.25 ms^-1
The force that the left team pulls with is 1000 N. If the right team's total mass is 300 kg and they accelerate by 1.2 m/s2, what is the force of resistance on the right team
Answer:
the force of resistance on the right team is 360 N
Explanation:
Given;
force of the left team, = 1000 N
total mass of the right team, m = 300 kg
acceleration of the right team, a = 1.2 m/s²
The force of resistance of the right team is calculated as;
Force = mass x acceleration
Force, F = 300 x 1.2
Force = 360 N
Therefore, the force of resistance on the right team is 360 N
The search for black holes involves searching for The search for black holes involves searching for Group of answer choices single stars that emit large amounts of X-rays. a stellar core greater than 3 solar masses large spherical regions from which no light is detected. pulsars with periods less than one millisecond. pulsars that are orbited by planets.
Answer:
Large spherical regions from which no light is detected
Explanation:
A black hole is an object that has an extremely high density such that it possesses very powerful gravitational force that prevents the escape of all objects including light from it, and consumes nearby objects.
Due to the power of the gravitational force of a black hole, at the center, objects are infinitesimally compressed resulting in the inapplicability of the concept of space and time and the location is known as a singularity
Therefore, the search for black holes involves searching for large spherical regions from which no light is detected.
Try working backward from the desired goal to the starting point or current state. This advice describes a
Answer:
heuristic.
Explanation:
Psychology can be defined as the scientific study of both the consciousness and unconsciousness of the human mind such as feelings, emotions and thoughts, so as to understand how it functions and affect human behaviors in contextual terms.
This ultimately implies that, psychology focuses on studying behaviors and the mind that controls it.
A heuristic is an automatic mental shortcut or rule of thumb that avail people the opportunity to make quick and efficient judgement in decision-making process, as well as proffering solutions to a problem. Thus, it allows people to make decisions, pass probability judgement or proffer solutions to problem quickly and efficiently while applying minimal mental effort.
Basically, a heuristic helps an individual to shorten the decision-making time while paying less attention on thinking of his or her next course of action.
Hence, when you're advised to try working backward from the desired goal to the starting point or current state. This advice describes a heuristic.
Compared to the inertia of a 1-kilogram mass, the inertia of a 4-kilogram mass is
Explanation:
The inertia of a 4 kg mass is four times as great as a 1 kg mass.
Find the transformation matrix that rotates a rectangular coordinate system through an angle of 60 about axes equal angels with original three coordinate axes
Answer:
[tex]M = \left[\begin{array}{ccc}cos \ 60&0\\0&-sin \ 60\end{array}\right][/tex]
Explanation:
To find the matrix, let's decompose the vectors, the rotated angle is (-60C) for the prime system
x ’= x cos (-60)
y ’= y sin (-60)
we use
cos 60 = cos (-60)
sin 60 = - sin (-60)
we substitute
x ’= x cos 60
y ’= - y sin 60
the transformation system is
[tex]\left[\begin{array}{ccc}x'\\y'\end{array}\right] = \left[\begin{array}{ccc}cos 60&0\\0&-sin60\end{array}\right] \ \left[\begin{array}{ccc}x\\y\end{array}\right][/tex]x '
the transformation matrix is
[tex]M = \left[\begin{array}{ccc}cos \ 60&0\\0&-sin \ 60\end{array}\right][/tex]
Using diagram 1.1 and diagram 1.2, compare the number of turn of the coils, the pattern of the iron fillings and the angle of deflection of the ammeter pointer
Answer:
The number of turns in the second coil is more than the coil 1.
Explanation:
The magnetic field lines are the imaginary path on which an isolated north pole moves if it is free to do so.
The tangent at any point to the magnetic field line, gives the direction of magnetic field at that point.
More be the crowd ness of magnetic field lines more is the strength of magnetic field.
Here the crowd ness of magnetic field lines is more in figure 2 , so the magnetic filed in figure 2 is more than 1. It shows that the number of turns in the second coil is more than the 1 and also the current in the coil 2 is more than 1 .
How do the rocks in the mantle move?
A. They do not move.
B. They move in convection currents.
C. They flow like water.
D. They move on top of the crust.
Answer:
b. they move in convection currents.
Explanation:
i learned this in 4th grade
The 75.0 kg hero of a movie is pulled upward at a constant velocity by a rope. What is the tension on the rope?
Answer:
750 N
Explanation:
the tension on the rope is the weight of the hero
What is the meaning of the word "force"?
Answer:
Explanation:
The word force has a precise meaning. A force is exerted on one object by another. The idea of a force is not limited to living things or non-living things. All objects (living and non-living) can apply a force on or to another object also all objects (living and non living) can be affected by forces.
Classes. frequency
0-20 2
20-40. 2
40-60. 3
60-80 12
80-100 18
100-120 5
120-140. 2
Find mean, median and mode
Answer:
The mean is 79.[tex]\overline {54}[/tex]
The median is 80 - 100
The mode is 80 - 100
Explanation:
The given table is presented as follows;
[tex]\begin{array}{lcrc}Classes&Mid \ point &Frequency &Frequency \times Mid \ point\\0 - 20&10& 2&20\\20-40&30&2&60\\40-60&50&3&150\\60-80&70&12&840\\80-100&90&18&1620\\100-120&110&5&550\\120-140&130&2&260\end{array}[/tex]
The mean of a class of values, [tex]\overline x[/tex] = ∑(Frequency × Midpoint)/∑(Frequency)
Therefore, we get;
[tex]\overline x[/tex] = (20+60+150+840+1620+550+260)/(2+2+3+12+18+5+2) = 79.[tex]\overline {54}[/tex]
The mean, [tex]\overline x[/tex] =79.[tex]\overline {54}[/tex]
The median class = The middle value lass = The class at the 22 nd value = 80 - 100
The median = 80 - 100
The modal class = The class with the highest frequency = 80 - 100
The mode = 80 - 100
what do you mean by time?
how to answer thiss helppp
Answer:
Look at work
Explanation:
Your given the mass of planet M and radius as well as second mass.
Use universal gravitation law to find force of gravity
Fg= Gm1m2/r^2
Plug in givens
Fg= 553.6 N
Use newtons second law
Fg= ma
553.6N=5a
solve for a= 110.72m/s
Weight is 553.6N
Clothes are flung to the sides of a round tub during the spin-cycle of a washing machine.If the tub's period of rotation is 0.2s and the tub's radius is 35cm,answer the related qestions below: (a)The frequency of roation (b)The circumference of rotation (c)The spinning of speed (d)The centripetal acceleration (e)The centripetal force of rotation if total mass rotated is 30kg (f)The power of washing machine
Answer:
Explanation:
First I need to tell you that I used .20 s for the period of rotation instead of just .2, and I used 30.0 kg for the mass instead of just 30. The reason being that both those numbers as stated in the problem only have 1 significant digit and that's not generally enough to get the accuracy you're looking for. Adding a 0 to the ends of each of those numbers doesn't change the value of the numbers, only the number of sig fig's in each. Beginning with a:
a. [tex]f=\frac{1}{T}[/tex] so [tex]f=\frac{1}{.2}[/tex] and f = 5.0 Hz
b. The circumference is the distance around the outside of the washer's drum. We need to find that, but before we do, I'm going to state the radius in meters instead of cm. 35 cm = .35 m. Therefore,
C = 2(3.1415)(.35) so
C = d = 2.2 m
c. The speed of the washer is found in d = rt, where r is the rate and our velocity and d is the distance around the outside of the drum (circumference). Therefore,
2.2 = v(.20) so
v = 11 m/s
d. The centripetal acceleration has an equation
[tex]a_c=\frac{v^2}{r}[/tex] so
[tex]a_c=\frac{(11)^2}{.35}[/tex] and
[tex]a_c=\frac{121}{.35}[/tex] so
[tex]a_c=350\frac{m}{s^2}[/tex]
e. The centripetal force has an equation
[tex]F_c=\frac{mv^2}{r}[/tex] and
[tex]F_c=\frac{(30.0)(11)^2}{.35}[/tex] and
[tex]F_c=[/tex] 1.0 × 10⁴ N
f. The equation for Power is
[tex]P=\frac{W}{t}[/tex] where W is work and W = FΔx (force times displacement). Therefore,
[tex]P=\frac{(1.0*10^4)(2.2)}{.20}[/tex] so
P = 1.1 × 10⁵ Watts
A jet plane lands at a speed of 100 m/s and can accelerate at a maximum rate of -5.00 m/s^2 as it comes to a rest.
(a from the instant the plane touches the runaway, what is the minimum time needed before it can come to a rest?
(b Can this plane land on a runaway that is only 0.800 km long?
shown work pls will reward alot of points
Answer:
a) t = 20 s, b) x = 1000 m, As the runway is only 800 m long, the plane cannot land at this distance
Explanation:
This is a kinematics exercise
a) in minimum time to stop,
v = vo + at
v = 0
t = -v0 / a
we calculate
t = -100 / (5.00)
t = 20 s
b) Let's find the length you need to stop
v² = vo² + 2 a x
x = -v0 ^ 2 / 2a
x = - 100² / 2 (-5.00)
x = 1000 m
As the runway is only 800 m long, the plane cannot land at this distance.
What kind of waves are present during an earthquake?
Answer:
There are four main types of earthquake waves:
P-waves S-waves (which are body waves), Rayleigh waves Love waves (which are surface waves).HOPE IT HELPS!!
A student sects a leaf of length 7.2 cm to draw. Her drawing is 28.8 cm in length. What is the magnification of the drawing?
a) x4
b) x207.36
c) x0.25
d) x36
Answer:
A) x4
Explanation:
Magnification is equal to image size divided by the actual size, or M = I/A.
The image size is the student's drawing, which is 28.8 cm, and the actual size is 7.2 cm. Divide them, and cancel out the units, and you should get:
28.8 cm/7.2 cm = 4
