Answer:
Coefficient of kinetic friction = 0.38 (Approx.)
Explanation:
Given:
Applied force = 45 N
Mass of wooden crate = 12 kg
Find:
Coefficient of kinetic friction
Computation:
Coefficient of kinetic friction = Applied force / (Mass)(Acceleration due to gravity)
Coefficient of kinetic friction = 45 / (12)(9.8)
Coefficient of kinetic friction = 45 / 117.6
Coefficient of kinetic friction = 0.3826
Coefficient of kinetic friction = 0.38 (Approx.)
Sound waves require a medium to travel. *
True
False
Answer:
false
Explanation:
Answer:
true
Explanation:
Space is not a medium. and we can not her anything in space. therefore you need a medium in order to hear sound waves.
A net force of 60 N north acts on an object with a mass of 30 kg. Use Newton's second law of
motion to calculate the amount of acceleration the object will experience. Then explain how the
amount of acceleration will change if the net force or the mass of the object increases.
Answer:
Explanation:
F = ma. For us, this looks like
60 = 30a and
a = 2 m/s/s
If the force goes up to, say, 90, then
90 = 30a and
a = 3...if the force goes up, the acceleration also goes up.
If the mass goes up to say, 60, and the force stays the same, then
60 = 60a and
a = 1...if the mass goes up, the acceleration goes down.
Two rigid rods are oriented parallel to each other and to the ground. The rods carry the same current in the same direction. The length of each rod is 1.1 m, while the mass of each is 0.10 kg. One rod is held in place above the ground, and the other floats beneath it at a distance of 11 mm. Determine the current in the rods.
Answer:
220 A
Explanation:
The magnetic force on the floating rod due to the rod held close to the ground is F = BI₁L where B = magnetic field due to rod held close the ground = μ₀I₂/2πd where μ₀ = permeability of free space = 4π × 10⁻⁷ H/m, I₂ = current in rod close to ground and d = distance between both rods = 11 mm = 0.011 m. Also, I₁ = current in floating rod and L = length of rod = 1.1 m.
So, F = BI₁L
F = (μ₀I₂/2πd)I₁L
F = μ₀I₁I₂L/2πd
Given that the current in the rods are the same, I₁ = I₂ = I
So,
F = μ₀I²L/2πd
Now, the magnetic force on the floating rod equals its weight , W = mg where m = mass of rod = 0.10kg and g = acceleration due to gravity = 9.8 m/s²
So, F = W
μ₀I²L/2πd = mg
making I subject of the formula, we have
I² = 2πdmg/μ₀L
I = √(2πdmg/μ₀L)
substituting the values of the variables into the equation, we have
I = √(2π × 0.011 m × 0.1 kg × 9.8 m/s²/[4π × 10⁻⁷ H/m × 1.1 m])
I = √(0.01078 kgm²/s²/[2 × 10⁻⁷ H/m × 1.1 m])
I = √(0.01078 kgm²/s²/[2.2 × 10⁻⁷ H])
I = √(0.0049 × 10⁷kgm²/s²H)
I = √(0.049 × 10⁶kgm²/s²H)
I = 0.22 × 10³ A
I = 220 A
Can someone please help me with this its worth all the points i have left
Answer:
1. Yes
2. Yes
3. 292 joules
4. 90 watts
5. By increasing the force
Explanation:
Have a wonderful day :)
A beam strikes an irregular mirror and is reflected as shown below. The angle formed by the incoming beam and the reflected beam is 10 degrees. What is the angle of the mirror's surface (measured against vertical) at the location where the beam strikes the mirror?
A. The mirror's surface is angled 5 degrees upward where the laser strikes it.
B. The mirror's surface is angled 5 degrees downward where the laser strikes it.
C. The mirror's surface is angled 10 degrees upward where the laser strikes it.
D. The mirror's surface is angled 10 degrees downward where the laser strikes it.
Answer:
the correct answer is B
Explanation:
The law of reflection states that the angles of incidence and reflection on a surface are the same, the two rays and the normal are in the same part of the surface.
In this exercise indicate that the angle between the incident and reflected ray is 10, therefore the angle with respect to the normal that is a vertical line at the point of contact of the ray must be 5
Consequently the correct answer is B
which of the two bodies a and b in the following graph is moving with higher speed and why
.........................................
pls say it fst its very urgent
Jorge tightens a bolt on his bicycle with a wrench that is 0.20 m long. If he pulls perpendicularly on the end of the wrench with a force of 140 N, how much torque does he apply ?
Answer:
28Nm
Explanation:
Torque is expressed as the prduct of force and radius
Given
Force = 140N
radius = 0.20m
Torque = 140 * 0.2
Torque = 140 * 1/5
Torque = 28Nm
Hence the amouunt of torque applied is 28Nm
The length of a planet's day is determined by it's
Answer: "People will say the length of a day is determined by just the rotation rate of a planet, but that isn’t entirely true. The orbit around its sun also factors in. What we define as a day is the time between when the Sun is highest in the sky until the next time the Sun is at the highest point in the sky. This isn’t just the time it takes the Earth to rotate once on its axis, though. This is because, as the Earth is rotating, it’s also moving relative to the Sun"
Which term BEST describes energy
stored in batteries and food?
potential energy
kinetic energy
heat energy
chemical energy
3. How do energy transformations, energy transfers, and conservation of energy allows you to track how energy moves through in a system?
Answer:
The law of conservation of energy states that when one form of energy is transformed to another, no energy is destroyed in the process. According to the law of conservation of energy, energy cannot be created or destroyed. So the total amount of energy is the same before and after any transformation
Explanation:
The energy in a system always transforms from one form to another without any significant loss or addition. It simply changes from one form to another with the effect of numerous external influences.
What is Energy transformation?Energy transformation may be defined as the process through which energy can convert from one form to another. It also illustrates the migration of energy from one place to another due to physical factors.
According to the law of conservation of energy, in a closed system energy can neither be created nor destroyed. The total amount of energy remains the same before and after the process of transformation.
Therefore, the energy in a system always transforms from one form to another without any significant loss or addition.
To learn more about Energy transformations, refer to the link:
https://brainly.com/question/16917873
#SPJ2
A tugboat can do 9,500,000 J of work through a distance of 35 m. What is the force exerted by the tugboat?
Answer:
271,428 4/7 N
Explanation:
Work done = force x distance.
9,500,000 = 35(force)
Force = 9,500,000 ÷ 35 = 271,428 4/7 N
Particles that attract each other are
A. two electrons.
B. two protons.
C. one proton and one electron.
D. one proton and one neutron.
A star produces energy by:
A: creating helium from hydrogen in its core.
B: reflecting energy from nearby stars.
C: absorbing and releasing the matter of other stars.
D: rotating quickly on its axis.
Here, the hydrogen atoms are combined to form a helium atom, and during this process of fusion, a significantly large amount of energy is released. Thus, stars produce a large amount of energy by forming helium from the combination of hydrogen in its core. Hence, the correct answer is option (C).
Answer:
A. Creating helium from hydrogen in its core.
Explanation:
Sacrificed my grade for points I hope it helps
20 POINTS:
Why does the initial hill of a roller coaster need to be steep?
Answer: A roller coaster does not have an engine to generate energy. The climb up the first hill is accomplished by a lift or cable that pulls the train up. This builds up a supply of potential energy that will be used to go down the hill as the train is pulled by gravity
Hope this helps! Good luck with future homework and exams!
Why does the needle of a compass point north?
a. Because the southern pole of the Earth's magnet repels it.
b. Because the southern pole of the Earth's magnet is in the north.
Because the northern pole of the Earth's magnet is in the north
d. Because the Earth's core is made of steel.
C.
Answer:
b. Because the southern pole of the Earth's magnet is in the north.
Explanation:
This is very weird to think about but Earth's southern magnetic pole is in Earth's geographic north. So when compass points north, it is actually getting attracted to the southern magnetic pole (that is actually located in the north direction- geographic location- in earth).
A 330.-ohm resistor is connected to a 5.00-volt battery. What is the current through the resistor?
Answer:
From Ohms Law
V=IR
V=5volts
R=33.0hms
I=V/R
I= 5/330
=0.0152A
The current flowing through the cross-section of the resistor is 0.0152A.
Given the data in the question;
Resistance; [tex]R = 330ohm[/tex]Voltage; [tex]V = 5.00V[/tex]Current; [tex]I = \ ?[/tex]Ohm's lawOhm's law states that "the current flowing through the cross-section of a conductor is directly proportional to the voltage across it".
It is expressed as;
[tex]V = IR[/tex]
Where V is voltage, I is current and R is the Resistance.
To determine the current flowing through the resistor, we substitute our given values into the expression above.
[tex]V = IR\\\\I = \frac{V}{R}\\ \\I = \frac{5.00V}{330\ Ohm} \\\\I = 0.0152A[/tex]
Therefore, the current flowing through the cross-section of the resistor is 0.0152A.
Learn more about Electric current here: https://brainly.com/question/2264542
which of the following is a vector physical quantity
a. speed
b. energy
c. mass
d. displacement
Answer:
D. displacement
Explanation:
Vector quantities have both magnitude and direction.
Scalar quantities have only magnitude.
The point A on the above graph is an example of
extrapolation
variation
interpolation
average method
Answer:
Interpolation
Explanation:
The graph shows that it falls between 2 values and interpolation means that you estimate the unknown values that fall between the 2 values. Hope this helps!
The data point A is between two given data points and it lies within the line connecting the data points, thus we can conclude that point A is an example of interpolation.
Extrapolation is the process of extending a line connecting the data points beyond the given data points to make inferences based on the previous trend of the data set. This helps us to understand what will happen in the future if the trend continues in the same manner.
Interpolation is the process of determining an unknown variable between two known variables. In this process the data point is located within the line connecting the data points.
In this given graph, the data point A is between two given data points and it lies within the line connecting the data points, thus we can conclude that point A is an example of interpolation.
Learn more here: https://brainly.com/question/11958294
If a beaker with 300 ml of 20°C water is poured into a beaker with 400 ml of 30°C water, what is the final temperature?
Answer:
Explanation:
A nucleus with mass number 229 emits a 3.443 MeV alpha particle. Calculate the disintegration energy Q for this process, taking the recoil energy of the residual nucleus into account.
Answer:
3.504 MeV
Explanation:
Given that;[tex]\frac{A}{Z} X ---->\frac{A-4}{Z-2} Y +\alpha + Q[/tex]
Also;
[tex]Q= KE_{\alpha } (M_{Y} + M_{\alpha } /M_{Y[/tex])
Mass number of X = 229
Mass number of Y = 225
Mass number of alpha particles = 4
Kinetic energy of alpha particles = 3.443 MeV
Q = 3.443 MeV (225 + 4/225)
Q= 3.504 MeV
Two light waves of equal wavelength, lambda, are emitted in phase from separate sources and propagate to a common point P. Light wave 1 must travel a longer distance (d1) than light wave 2 (d2) to reach point P, where d1 – d2 is equal to the path difference between the two light waves. If the two waves interfere constructively at point P, what must be true about the path difference between the two light waves?
Answer:
The path difference must be equal to an integral (1 * lambda, 2 * lambda, -------n * lambda) number of wavelengths for constructive interference to occur.
What are some core features of waves in physics?
Answer:
Waves are disorders that travel through a fluid medium. Several simple wave features include frequency, period, wavelength, and amplitude.
Explanation:
A positive charge is moving across a room from south to north. A magnetic field runs from east to west. In what direction is the magnetic force on the moving positive charge?
Answer:
the force is on the z axis, coming out of the blade
Explanation:
The direction of the magnetic force is given by the right hand rule,
For a positive charge, the thumb points in the direction of velocity, the other fingers extended in the direction of the magnetic field, and the palm points in the direction of force.
In this case.
Thumb points North
The fingers extended is in the east - west direction parallel to the blade
The palm is sticking out of the leaf, in the z direction
the answer is the force is on the z axis, coming out of the blade
Two people are sitting on wheeled chairs 1 metre apart. Person A is holding a 2kg ball. Person A throws the ball to Person. What happens to person A? Explain.
a.) their chair stays still
b.) chair rolls backwards
c.) chair rolls forwards
Answer:
B - Person A's chair rolls backwards.
Explanation:
This can be seen simply through the Conservation of Momentum. When the ball is thrown to be, the ball's momentum(+m) is transfererd to B, so B's chair moves forward(think about it - it makes sense, doesn't it?), meaning A's chair moves backwards.
So, B.
EXTRA TIP: Try drawing a diagram to help you!
plsss helpp i really need this now thank u ❤️
Answer:
10.
parabolic
11.
Entirely horizontal
12.
45°
Usain bolt ran the 200m race within 19.19 seconds. Calculate the speed of Usain bolt during the race
Answer: [tex]10.42\ m/s[/tex]
Explanation:
Given
Usain Bolt ran the race with a length [tex]200\ m[/tex]
Time is taken to complete it [tex]t=19.19\ s[/tex]
We know, [tex]\text{Distance}=\text{speed}\times \text{time}[/tex]
Insert the values
[tex]\Rightarrow 200=v\times 19.19\\\\\Rightarrow v=\dfrac{200}{19.19}\\\\\Rightarrow v=10.42\ m/s[/tex]
So, the speed of Usain Bolt is [tex]10.42\ m/s[/tex]
Which object will take the most force
to accelerate? *
4 kg
6 kg
8 kg
02 kg
Answer:
I think it might be 8kg grams because it is bigger
A parallel combination of 3ohms and 4ohms resistor is connected in series with a resistor of 4ohms and a battery of negligible resistance. Calculate the effective resistance in the circuit
Answer:
Explanation:
Equivalent resistance of parallel combination of two resistors of 3 ohms and 4 ohms .
R₁ = 3 x 4 / ( 3 + 4 )
= 12 / 7 = 1.7 ohms .
This equivalent resistance is connected with 4 ohms in series
Total resistance = 1.7 ohms + 4 ohms
= 5.7 ohms.
Hence effective resistance of the circuit = 5.7 ohms .
Einstein's theory of general relativity is currently the best explanation of gravity.Why has this theory not been replaced with a new one
Answer:
Option C, It still explains the experimental evidence pertaining to gravity
Explanation:
Please find the attachment
Answer:
A.) It will remain the best explanation, because no one has come up with a better one yet
Explanation:
ik its a lot but can u help
Answer:
your correct ans is D.
object float in liquid when its density is less than liquid and sinks when its density is more than liquid..
stay safe healthy and happy.