Answer:
vddvdvvdvffdfvd
Explanation:
Câu 20: Chọn câu sai:
A. Công là đại lượng vô hướng B. Công không có tính tương đối
C. Công phụ thuộc vào đường đi D. Công có giá trị đại số
Answer:
fr
Explanation:
How are acceleration and velocity related
A: An object with constant velocity also has constant acceleration
B: Acceleration and velocity are not related. C:Acceleration describes how fast the velocity of an object is changing,
D: Acceleration only occurs when the speed of an object changes, but velocity can change if speed or direction changes
Answer:
answer is C
Explanation:
acceleration is rate of changing velocity in a time
Atoms of which two elements could combine with atoms of carbon (C) to
form covalent bonds?
A. S
B. Na
C. N
D. K
E. Ca
Answer:
Correct answer is letter E.Ca
The surface of a running track is made of rubber. A heavy trolley is pulled on to the track and it exerts a large force on the rubber track. State two effects that this force has on the rubber
Answer:
hi im from canada so can we be friends
An instructor gives a demonstration in which he makes a standing wave on a long thin slinky. The slinky is 6.0 meters long. If you see 3 loops on the slinky when the instructor shakes the end of the slinky at a rate of 2.50 cycles per second, then the speed (in m/s) of transverse traveling waves on the slinky is
The characteristics of standing waves allows to find the result for the speed of the wave is:
The speed wave is: v = 10 m / sThe wave is a way of transmitting energy without mass displacement, , in the attachment we can see a diagram of the standing wave.
Each cycle corresponds to half a wavelength, they indicate that the frequency is 2.50 Hz and there are three cycles, so the wavelength is:
L = [tex]n \frac{\lambda}{2}[/tex]
λ = 2L/n
λ = 2 6 /3
λ = 4 m
Wave speed is related to wavelength and frequency
v = λ f
v = 4 2.5
v = 10 m / s
In conclusion, using the characteristics of standing waves we can find the result for the speed of the wave is:
The wave speed is: v = 10 m / sLearn more here: brainly.com/question/12536719
10. The SI unit of the solid angle is
a) Degree
b) Steradian
c) Revolution
d) Radian
The S.I unit of solid angle is steradian, or square radian (symbol: sr).
Bill is sitting on a tree limb that is 4 meters above the ground with a water balloon. He wants to drop the water balloon so that it falls on his friend Tim who is approaching on a bike at a constant speed of 8 meters per second. How far away should Tim be from a point directly under bill when bill drops the balloon?
Answer:
wow poor bill
Explanation:
The pulley shown in the attached diagram has a diameter of 30 centimeters and a mass of 19 kilograms. The pulley is a solid disk with an axle through its center.
(a.) What is the moment of inertia of the pulley?
(b.) What is the magnitude of the net torque on the pulley about its axis
(c.) What is the direction of the net torque on the pulley?
(d.) What is the magnitude of the angular acceleration of the pulley?
(e.) What is direction of the angular acceleration?
Answer:
Explanation:
a) I = ½mR² = ½(19)(0.15²) = 0.21375 kg•m²
b) τ = Fnet(r) = (25 - 12)(0.15) = 1.95 N•m
c) CCW
d) a = τ/I = 1.95 / 0.21375 = 9.12280701... = 9.1 rad/s²
e) CCW
11. A plow pushes 100 kg of snow with 300 N of force. How much is the pile of snow
accelerated?
Answer:
Explanation:
This is an application of Newton's second Law.
Formula
F = m * a
F = 300 N
m = 100 kg
a = ?
F = m * a
300N = 100 kg * a Divide by 100
300N/100kg = a
a = 3 m/sec^2
Each substance has a unique set of properties that depends on the kinds of atoms it has and how the atoms are connected, or bonded. Bonding is related to the electrons in an atom, and there are different kinds of bonds. As a result, some substances can have the same atoms but different bonds. Substances that are different but have the same atoms are called allotropes. Allotropes have very different properties.
Diamond and graphite are well-known allotropes. Graphite is used in pencils for writing and is sometimes called lead. Diamond is colorless and transparent, and is one of the hardest substances known. Graphite is dark gray and soft. When we write, layers of graphite easily transfer from the pencil to the paper. Although they’re different, diamond and graphite each only contain one kind of atom—carbon.
How do you think the bonds between carbon atoms might be different in diamond and graphite? Use household materials to build physical models to help you develop your ideas. Describe what you learned from your models. What other kinds of allotropes are there? What kinds of properties and atomic bonds do they have?
Answer:
C - the atom is all about the proton number.
An isotope of an atom is the same element with a different number of neutrons.
Explanation:
2. a) A disc rotates about its axis at speed 25 revolutions per minute and takes 15 s to stop. Calculate the
i) angular acceleration of the disc.
ii) number of rotation of the dise makes before it stops.
The statement shows a case of rotational motion, in which the disc decelerates at constant rate.
i) The angular acceleration of the disc ([tex]\alpha[/tex]), in revolutions per square second, is found by the following kinematic formula:
[tex]\alpha = \frac{\omega_{f}-\omega_{o}}{t}[/tex] (1)
Where:
[tex]\omega_{o}[/tex] - Initial angular speed, in revolutions per second.[tex]\omega_{f}[/tex] - Final angular speed, in revolutions per second. [tex]t[/tex] - Time, in seconds.If we know that [tex]\omega_{o} = \frac{5}{12}\,\frac{rev}{s}[/tex], [tex]\omega_{f} = 0\,\frac{rev}{s}[/tex] y [tex]t = 15\,s[/tex], then the angular acceleration of the disc is:
[tex]\alpha = \frac{0\,\frac{rev}{s}-\frac{5}{12}\,\frac{rev}{s}}{15\,s}[/tex]
[tex]\alpha = -\frac{1}{36}\,\frac{rev}{s^{2}}[/tex]
The angular acceleration of the disc is [tex]\frac{1}{36}[/tex] radians per square second.
ii) The number of rotations that the disk makes before it stops ([tex]\Delta \theta[/tex]), in revolutions, is determined by the following formula:
[tex]\Delta \theta = \frac{\omega_{f}^{2}-\omega_{o}^{2}}{2\cdot \alpha}[/tex] (2)
If we know that [tex]\omega_{o} = \frac{5}{12}\,\frac{rev}{s}[/tex], [tex]\omega_{f} = 0\,\frac{rev}{s}[/tex] y [tex]\alpha = -\frac{1}{36}\,\frac{rev}{s^{2}}[/tex], then the number of rotations done by the disc is:
[tex]\Delta \theta = 3.125\,rev[/tex]
The disc makes 3.125 revolutions before it stops.
We kindly invite to check this question on rotational motion: https://brainly.com/question/23933120
Consider the frame shown in (Figure 1). The suspended cylinder has a mass of 90 kg .
Determine the x and y components of reaction at pin B on BC using scalar notation.
Determine the x and y components of force at pin C using scalar notation.
A system in equilibrium has a moment sum of zero and the sum of upward
forces equal to the sum of the downward forces.
The correct values are;
The x and y component of the reaction at pin B are;
Bₓ = 1471.5 N
[tex]B_y[/tex] = 1103.625 N
The x and y component of the force at pin C are;
Cₓ = 588.6 N
[tex]C_y[/tex] = 220.725 N
Reasons:
The weight of the cylinder, W = 90 kg × 9.81 m/s² = 882.9 N
Considering member AB, gives;
[tex]\sum M_A[/tex] = [tex]B_y[/tex] × 2 - [tex]B_x[/tex] × 1.5 = 0 ⇒ [tex]B_y[/tex] = 0.75·Bₓ
Considering member CB, gives;
[tex]\mathbf{\sum M_C}[/tex] = -[tex]B_y[/tex] × 2 + 882.9 × 2.5 = 0 ⇒ [tex]B_y = \dfrac{882.9 \times 2.5}{2} = 1103.625[/tex]
[tex]B_y[/tex] = 0.75·Bₓ ⇒ [tex]B_x = \dfrac{B_y}{0.75} = \dfrac{1103.625}{0.75} = 1471.5[/tex]
The x and y component of the reaction at pin B are;
Bₓ = 1471.5 N, [tex]B_y[/tex] = 1103.625 N
[tex]\mathbf{\sum F_y}[/tex] = 0 ⇒ -[tex]C_y[/tex] + [tex]B_y[/tex] - 882.9 = 0 ⇒ [tex]-C_y[/tex] + 1103.625 - 882.9 = 0
[tex]C_y[/tex] = 1103.625 - 882.9 = 220.725
[tex]\sum F_x[/tex] = 0 ⇒ -Cₓ + Bₓ - 882.9 = 0 ⇒ -Cₓ + 1471.5 - 882.9 = 0
Cₓ = 588.6
The x and y component of the reaction at pin C are;
Cₓ = 588.6 N, and [tex]C_y[/tex] = 220.725 N
Learn more here:
https://brainly.com/question/24022332
A cabinet weighs 98N. What is the mass of the cabinet in kilogram?
Note: No need to write the units in your answer. Just the number only.
Write your solution and answer with units in your science portfolio.
Formulas: m=w/g: or w=mg
Answer:
the answer to ur questioj is 10 kg
A double concave lens is a ________ lens, and a double convex lens is a ______ lens.
a.
converging, diverging
c.
converging, converging
b.
diverging, converging
d.
diverging, diverging
Answer:
b. diverging, converging
Answer:diverging, converging
Explanation:
Which phrase describes an irregular galaxy O has a round shape O does not have a specific shape O has arms that extend from the center O is larger than other types of galaxies
Answer:
I think it does not have a specific shape
Explanation:
Irregular galaxies have no definite shape, which means that the second option is correct. They are definitely not round.
The "spiral galaxy" is the type of galaxy that has arms that extend from the center. These arms look "spiral," which influenced its name.
They are actually smaller than the other types of galaxies. This makes them prone to collisions.
The phrase that describes the irregular galaxy is that it does not have a specific shape. The correct option is B.
What is irregular galaxy?A galaxy with an undefined shape is an irregular galaxy with a large number of young stars and a large amount of gas and dust that is typically found near larger galaxies.
An irregular galaxy is a catch-all term for any galaxy that does not neatly fit into one of the Hubble classification schemes.
They have no discernible shape or structure and could have formed as a result of collisions, close encounters with other galaxies, or violent internal activity.
They lack beautiful spiral arms, but they do have dark patches of gas and dust. Some irregular galaxies appear to be the result of two galaxies colliding.
Thus, the correct option is B.
For more details regarding irregular galaxy, visit:
https://brainly.com/question/16258011
#SPJ5
A car accelerates at 4 m/s/s from rest. What is the car's velocity after it travels 20 m?
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
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
I WILL MARK BRAINLIEST !! PLEASE HELP!
Answer:
b
Explanation:
real answers only pls
Answer:
1. it spins
2. falls in a curve
3. falls flat on the floor
A baseball is hit straight up in the air with an initial velocity of 38 m/s
How long does it stay in the air?
How high does it go?
The time of motion or time spent in air by the baseball is 7.76 seconds.
The maximum height attained by the baseball is 73.67 m.
The given parameters;
initial velocity of the baseball, u = 38 m/sThe time of motion of the baseball is calculated using the first kinematic equation as follows;
v = u - gt
where;
t is the time to reach maximum heightv is the final velocity of the ball at the maximum height = 00 = u -gt
gt = u
[tex]t = \frac{u}{g} \\\\\t = \frac{38}{9.8} \\\\t = 3.88 \ s[/tex]
The time spent in the air = time of entire motion = 2(3.88 s) = 7.76 seconds
The maximum height attained by the ball is calculated using the second kinematic equation as shown below;
[tex]h = ut -\frac{1}{2} gt^2\\\\h = (38\times 3.88)\ - \ (0.5 \times 9.8 \times 3.88^2)\\\\h = 73.67 \ m[/tex]
Learn more here:https://brainly.com/question/8599327
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
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
PHYSICISTS NEEDED, THANK YOU, (10 POINTS)
Answer:
would it be 2.66666666667 or 2.7
Explanation:
what is one measurement needed to calculate the speed of an object
Answer:
The equation for speed is simple: distance divided by time. You take the distance traveled (for example 3 meters), and divide it by the time (three seconds) to get the speed (one meter per second).
Explanation:
A player kicks a soccer ball.
What is the reaction force?
A. The ball pushes back on the player's
foot.
B. The ground pushes back on the player.
C. The ground pushes back on the ball.
Answer:
the ground pushes back on the player
Answer:
c
Explanation:
force is every where so anything that goes up must come down
Which factors would increase heating of Earth, and which factors would decrease it
Answer:
So as sunlight continued to enter the box and the walls continued to warm, heat built up inside and increased the temperature.
a place-kicker must kick a football from a point 36.0 m (about 40 yards) from the goal. half the crowd hopes the ball will clear the crossbar, which is 3.05 m high. when kicked, the ball leaves the ground with a speed of 23.9 m/s at an angle of 51.5 degrees to the horizontal. (a) by how much does the ball clear or fall short of clearing the crossbar?
(b) does the ball approach the crossbar while still rising or while falling?
Explanation:
Let's calculate the components of the football's velocity:
[tex]v_{0x} = (23.9\:\text{m/s})\cos{51.5°} = 14.9\:\text{m/s}[/tex]
[tex]v_{0y} = (23.9\:\text{m/s})\sin{51.5°} = 18.7\:\text{m/s}[/tex]
a) The time it takes for the football to travel 36.0 m horizontally is
[tex]t = \dfrac{x}{v_{0x}} = \dfrac{36.0\:\text{m}}{14.9\:\text{m/s}} = 2.4\:\text{s}[/tex]
During this time, the y-displacement of the football is
[tex]y = v_{0x}t - \frac{1}{2}gt^2[/tex]
[tex]\:\:\:\:= (18.7\:\text{m/s})(2.4\:\text{s}) - \frac{1}{2}(9.8\:\text{m/s}^2)(2.4\:\text{s})^2[/tex]
[tex]\:\:\:\:= 16.7\:\text{m}[/tex]
This means that the football cleared the crossbar by 16.7 m - 3.05 m = 13.7 m
b) To determine whether the football was rising or falling while clearing the crossbar, let's look at the y-component of its velocity after 2.4 s:
[tex]v_y = v_{0y} - gt = 18.7\:\text{m/s} - (9.8\:\text{m/s}^2)(2.4\:\text{s})[/tex]
[tex]\:\:\:\:\:\:= -4.82\:\text{s}[/tex]
Since its sign is negative, this means that the football was already on its way down.
in a collision, a 25.0kg mass moving at 3.0m/s transfers all of its momentum to a 5.0kg mass. What is the velocity of the 5.0kg mass after the collision?
Answer:
Explanation:
The 25.0 kg mass has momentum before the collision of
p = 25.0(3.0) = 75 kg•m/s
If all this momentum gets transferred into a 5.0 kg mass, the velocity of the 25.0 kg mass will be zero and the velocity of the 5.0 kg mass will be
75 / 5.0 = 15.0 m/s
Getting this to occur will require an addition of a significant amount of energy via an internal explosion or release of spring potential energy. This can be shown by looking at kinetic energies.
Initial system kinetic energy is ½(25.0)3.0² = 112.5 Joules
After the collision, system kinetic energy is ½(5.0)25² = 1,562.5 Joules
so 1562.5 - 112.5 = 1450 Joules of energy must be released during the collision to complete this scenario.
The most efficient energy transfer without energy release is an ideal elastic collision. Had these two masses been in such a collision with the given initial conditions, the 5 kg mass would have moved away at 5.0 m/s taking with it 5(5) = 25 kg•m/s of momentum leaving the 25 kg mass with 75 - 25 = 50 kg•m/s of momentum and a velocity of 50/25 = 2.0 m/s. Both masses are now traveling in the same direction as the original velocity, but at different speeds. Notice kinetic energy is conserved in elastic collisions
½(25)2² + ½(5.0)5² = 112.5 Joules.
The only time one mass can transfer its entire momentum to another mass without additional energy addition or subtraction is when the two colliding masses are identical in magnitude. Think pool balls colliding on a table.
Give two examples of contact and non-contact forces and explain why they are contact and non-contact forces respectively.
The Two examples of contact forces are:
frictional force Contact force.The two examples of non contact forces are:
Gravitational forcemagnetic force.Contact forces happens due to the contact between two objects
Non Contact forces happens because there is no contact between two objects. There is no attraction.
A uniform string of length 0.50 m is fixed at both ends. Find the
wavelength of the fundamental mode of vibration. If the wave
speed is 300 mis, find the frequency of the fundamental and next
possible modes.
Answer:
configuration of string:
Node - Antinode - Node or N-A-N
This is 1/2 wavelength since a full wavelength is N-A-N-A-N
f (fundamental) = V / wavelength
F0 = 300 m/s / 1 m = 100 / sec
F1 = 300 m/s / .5 m = 600 / sec
Each increase is a multiple of the fundamental since the wavelength
increases by 1/2 wavelength to keep nodes at both ends of the string
identify impacts of air pollution
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