The object would have a centripetal acceleration a of
a = (12 m/s)² / (0.7 m) ≈ 205.714 m/s²
so that the required tension in the string would be
T = (0.5 kg) a ≈ 102.857 N ≈ 100 N
(rounding to 1 significant digit)
what is mechanics physics
A steady-state temperature difference of 85 K is impressed across a fiberglass layer of 13 cm thickness. The thermal conductivity of the fiberglass is 0.035 W/m K. Compute the heat transferred through the material per hour per meter squared.
Answer:
21.54W/m²
Explanation:
Heat transferred through the material is expressed as;
Q =K∆T/∆x
Given
Thermal conductivity k = 0.035W/mK
∆T is the change in temperature = 80K
∆x is the thickness = 13cm = 0.13m
Substitute the given values into the formula
Q = 0.035(80)/0.13
Q = 2.8/0.13
Q = 21.54W/m²
Hence the heat transferred through the material is 21.54W/m²
A tow truck applies a force of 2600 N on a 2100 Kg car for a period of 9 seconds. What is the magnitude of the change in the car’s momentum?
Answer:
P = 23400 [kg*m/s]
Explanation:
Momentum is defined as the product of force by the time of force duration. It can be determined by means of the following equation.
[tex]P=F*t[/tex]
where:
P = momentum [kg*m/s]
F = force = 2600 [N]
t = time = 9 [s]
Now replacing:
[tex]P=2600*9\\P=23400 [kg*m/s][/tex]
A 4.5-kW resistance heater in a water heater runs for 3 hours to raise the water temperature to the desired level. Determine the amount of electric energy used in both kWh and kJ.
Answer:
The electrical energy is 13.5 kWh or 48600 kJ
Explanation:
Given that,
The power of the resistance heater, P = 4.5 kW
The water heater runs for 3 hours to raise the water temperature to the desired level.
We need to find the amount of electric energy used in both kWh and kJ.
Energy = Power × time
E = 4.5 kW × 3 h
= 13.5 kWh
Since,
1 kWh = 3600 kJ
13.5 kWh = 48600 kJ
Hence, the required electrical energy is 13.5 kWh or 48600 kJ
A 2 kg toy car moves at a speed of 5 m/s.? If a child applies a 3 N force for 2 m in the same direction the car is already moving, how much work isdone on the car?
Answer:
its A
Explanation:
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Which ray diagram demonstrates the phenomenon of absorption?
tum
Answer:
hjbyvtf ghbj
Explanation:
uhgbnm,likjh
hii Happy New year can you all please answer this
Answer:
truuuuuuuuuuuuueeeeeeeee
Explain why this is synthesis reaction
Answer:
This is a synthesis reaction because two substances react to produce one substance.
Explanation:
Got it straight off plato.
Answer:
This is a synthesis reaction because two substances react to produce one substance.
Explanation:
I throw a thin uniform circular disc (think of a frisbee) into the air so that it spins with angular velocity ω about an axis which makes an angle α with the axis of the disc. Show that the magnitude of ω is constant.
Answer:
| w | = w√ ( sin^2 ∝ + cos^2∝ ) shows that w is independent of time hence it is constant
Explanation:
prove that the magnitude of w is constant
attached below is a detailed solution of the question
What is buoyancy? How is it related to the force of gravity?
Answer:
buoyancy is the ability to float on water or other liquids. this relates to the force of gravity because the stronger that force, the more likely it is to sink.
Explanation:
Egg A is dropped from a height of 1m onto the floor. Egg B is dropped from a height of 1m into a bucket of water. Which statement
correctly describes why Egg B does not break?
Answer:
maybe it's because a bucket of water has more density than egg B
Answer:
Egg B experiences less force over a shorter time
Explanation:
PLEASE ANSWER ASAP BEFORE MY TEACHER AND MY MOM KILLES ME PLEASE ASAP
The first person with the right answer gets to be a brainlest
In the attachment there is a density column where there is colour
Question: tell me why is the red at the bottom of the density column if it is the least dense
Answer:
because it’s on the bottom, and to get to that part of it, think of it like that scene from moana when they go down into the realm of monsters they go through the thick parts to get to the thin parts, soo the cube wouldn’t be nearly able to reach that level
Explanation:
Answer:
the red at the bottom should not count, but the red at the top is the least dense because it floats upon the other liquids
Explanation:
hope this helps
Two forces whose resultant is 100newton are perpendicular to each other. If one of them makes an angle of 60newton with the resultant. Calculate it magnitude
Answer:
100 N
Explanation:
Given that,
Two forces whose resultant is 100newton are perpendicular to each other.
If one of them makes an angle of 60newton with the resultant.
[tex]F_1=100\times \sin60=86.60\ N[/tex]
and
[tex]F_2=100\times \cos60=50\ N[/tex]
The magnitude of force,
[tex]F=\sqrt{F_1^2+F_2^2} \\\\F=\sqrt{86.6^2+50^2} \\\\F=99.99\ N[/tex]
or
F = 100 N
So, the magnitude of force is 100 N.
The energy lost during transformation is always in the form of:
chemical
heat
sunlight
mechanical
Answer:
heat
answer already there but yea just for da points
An object moving in simple harmonic motion has an amplitude of 0.02m and a maximum acceleration of 40m/s2 . what is the frequency of the system (in Hz)
Answer:
f = 7.11 Hz
Explanation:
Given that,
The amplitude of object in SHM, A = 0.02 m
The maximum acceleration of the object, a = 40 m/s²
We need to find the frequency of the system.
The maximum acceleration of the object in SHM is given by :
[tex]a=\omega ^2 A[/tex]
Where [tex]\omega[/tex] is angular frequency
[tex]\omega^2=\dfrac{a}{A}\\\\\omega=\sqrt{\dfrac{a}{A}} \\\\=\sqrt{\dfrac{40}{0.02}} \\\\\omega=44.721\ rad/s[/tex]
We know that,
[tex]f=\dfrac{\omega}{2\pi}\\\\f=\dfrac{44.721}{2\pi}\\\\f=7.11\ Hz[/tex]
So, the frequency of the system is 7.11 Hz.
3.7. A dog searching for a bone walks 3.50 m south, then 8.20 m at an angle 23.1 degrees north of east, and finally 15.0 m west. (a) What is the magnitude of the dog’s total displacement? (b) What is the direction of the dog’s total displacement where directly east is taken as zero degrees and counter-clockwise is positive?
Answer:
Explanation:
We shall represent displacement of dog in vector form , in terms of i , j , i representing east and j representing north .
Dog travels 3.5 m south .
Displacement D₁ = - 3.5 j
then dog travels 8.2 m , 23.1 degree north of east
Displacement D₂ = 8.2 cos23.1 i + 8.2 sin23 j
D₂ = 8.2 cos23.1 i + 8.2 sin23.1 j
= 7.54 i + 3.22 j
Third displacement
D₃ = - 15i
Total displacement = D₁ + D₂ + D₃
= - 3.5 j + 7.54 i + 3.22 j -15i
= - 7.46 i - 0.28 j
Magnitude of displacement = √ ( 7.46² + .28²)
= √(55.65 + .08 )
= 7.46 m
b ) Direction of displacement
If Ф be angle , displacement makes with west direction
TanФ = .08 / 55.65 = .00143
Ф = .082 degree south of west or almost west .
From east , this angle = 180 + .082 = 180.082 , counterclockwise .
The classic Millikan oil drop experiment was the first to obtain an accurate measurement of the charge on an electron. In it, oil drops were suspended against the gravitational force by a vertical electric field. Given the oil drop to be 1.00 um in radius and have a density of 920 kg/m^3.
a. Find the weight of the drop.
b. If the drop has a single excess electron, find the electric field strength needed to balance its weight.
Answer:
a) [tex]W=3.78\cdot 10^{-14}\: N[/tex]
b) [tex]E=2.36\cdot 10^{5} N/C[/tex]
Explanation:
a) The weight is just the mass of the drop times the acceleration of gravity.
[tex]W=mg[/tex]
Or in terms of density.
[tex]W=\rho Vg[/tex] (1)
If we consider the volume of a drop as spherical, we can find the volume (R=1 μm = 0.000001 m).
[tex]V=\frac{4}{3}\pi R^{3}[/tex]
[tex]V=\frac{4}{3}\pi (10^{-6})^{3}[/tex]
[tex]V=\frac{4}{3}\pi 10^{-18}[/tex]
[tex]V=4.19\cdot 10^{-18}\: m^{3}[/tex]
Then, using equation (1), the weight will be:
[tex]W=920\cdot 4.19\cdot 10^{-18}\cdot 9.81[/tex]
[tex]W=3.78\cdot 10^{-14}\: N[/tex]
b) To balance the weight, the electric field times the charge must be the same value in the opposite direction, which means:
[tex]W-qE=0[/tex]
[tex]E=\frac{W}{q_{electron}}[/tex]
[tex]E=\frac{3.78\cdot 10^{-14}}{1.60\cdot 10^{-19}}[/tex]
[tex]E=2.36\cdot 10^{5} N/C[/tex]
I hope it helps you!
The range is the horizontal distance from the cannon when the pumpkin hits the ground. This distance is given by the product of the horizontal velocity (which is constant) and the amount of time the pumpkin is in the air (which is determined by the vertical component of the initial velocity, as you just discovered). Set the initial speed to 14 m/s, and fire the pumpkin several times while varying the angle between the cannon and the horizontal. For which angle is the range a maximum (with the initial speed held constant)
Answer:
x(max) = 20 m
Explanation:
In projectile shoot e have:
V₀y = V₀*sin θ
V₀ₓ = V₀*cos θ
V₀ initial speed
θ shotting angle
Vₓ = V₀ₓ = V₀*cos θ during the trajectory
Vy = V₀y - g*t
And when Vy = 0 h is maximun and the time to reach y maximum is half of the overall time.
According to that
Vy = 0 V₀y = g*t t = V₀y/g
t = 14* sinθ / 9,8
t = 1,43 *sinθ s
And overall time is T = 2* 1,43*sinθ
t = 2,86*sinθ
x = V₀ₓ * t s
x = 14*cosθ * 2,86* sinθ
x = 40 * cosθ * sinθ
Lets take two very well know sin cos pairs
for ∡ 30 ∡ 45 ∡60
and 30 and 60 are complementary angles for boths
cosθ * sinθ is the same ( 1/2)*(√3/2)
cosθ * sinθ = 0,433 and
x = 40* 0,433
x = 17,32 m
For ∡ 45 boths sin45 and cos45 are equal √2/2
In this case
x = 40*(√2/2)*(√2/2)
x = 40* 2/4
x = 20 m
And that is the maximum range
x(max) = 20 m
The scientific method is a process that scientists use to understand the physical world. Place the four basic steps of the scientific method in the correct order, from start to finish.
a. Observation of physical world.
b. Create hypothesis about observation.
c. Test conscquences of hypothesis
d. Report outcome
e. Adjust results to agree with popular opinion
Answer:
a,b,c,e,d
Explanation:
The typical approach by the scientists use to understand the physical world includes the following steps:
Identifying a Problem
Researching the Information
Stating a Hypothesis (Possible Solution)
Testing the Hypothesis
Gather Data
Analysis of the Data
Stating a Conclusion
Publishing the Result
Therefore, according to the question the correct order would be:
a. Observation of physical world.
b. Create hypothesis about observation.
c. Test consequences of hypothesis
e. Adjust results to agree with popular opinion
d. Report outcome
4. True or False. Improving your muscular endurance can improve your
power *
Answer:
it's true
Explanation:
A strong body allows you to perform movements and activities that require power without getting tired.
A spring with a rest length of 0.7 m has a spring constant of 70 N/m. It is stretched and now has a length of 2.5 m. What is the potential energy stored in the spring?
____ J
Answer:
113.4 J
Explanation:
Elastic Potential Energy
Is the energy stored in an elastic material like a spring of constant k, in which case the energy is proportional to the square of the change of length Δx and the constant k.
[tex]\displaystyle PE = \frac{1}{2}k(\Delta x)^2[/tex]
The spring has a natural length of 0.7 m and a spring constant of k=70 N/m. When the spring is stretched to a length of 2.5 m, the change of length is
Δx = 2.5 m - 0.7 m = 1.8 m
The energy stored in the spring is:
[tex]\displaystyle PE = \frac{1}{2}70(1.8)^2[/tex]
PE = 113.4 J
Which is not part of a DC motor?
Answer:
The correct answer to the question will be compass i.e compass is not a part of a DC motor. Various parts of a DC motor are coil of wire, armature, field magnets, brushes and commutator. The coil of wire plays a vital role in DC motor.
Explanation:
PLEASE HELP THIS IS TIMED!
a constant force is causing a sled to accelerate at 4 m/s^2. If the mass is suddenly cut in half what will the new acceleration be
A population’s exponential growth is the number of offspring produced over a given time period.True or false
You are assigned the design of a cylindrical, pressurized water tank for a future colony on Mars, where the acceleration due to gravity is 3.71 meters per second per second. The pressure at the surface of the water will be 150 KPa , and the depth of the water will be 14.4 m . The pressure of the air in the building outside the tank will be 88.0 KPa .
Find the net downward force on the tank's flat bottom, of area 2.15 m2 , exerted by the water and air inside the tank and the air outside the tank.
Answer: F = 6262.2 kN
Explanation: Pressure is defined as force per area. But pressure varies according to the depth of a fluid: in air, it decreases the higher the altitude, while in water, it increases the deeper you go.
So, at the bottom of the tank, besides the pressure of air inside the tank and air outside the tank, there is pressure of water due to its depth.
Pressure due to the depth is calculated as
[tex]P=h.\rho.g[/tex]
h is the depth in m
ρ is density of the fluid, in this case is water, so ρ = 997 kg/m³
g is acceleration due to gravity, which, in this case, is 3.71 m/s²
Then, pressure at the bottom of the tank due to variation in depth is
[tex]P=14.4(997)(3.71)[/tex]
P = 53263.73 Pa or 53.26 kPa
Assuming positive referential is downward, all pressures at the bottom point down, so total or resultant pressure is:
[tex]P_{r}=P_{1}+P_{2}+P_{3}[/tex]
[tex]P_{r}=150+88+53.26[/tex]
[tex]P_{r}=[/tex] 291.26 kPa
At last, pressure is force per area:
[tex]P=\frac{F}{A}[/tex]
[tex]F=P.A[/tex]
[tex]F_{r}=P_{r}.A[/tex]
[tex]F_{r}=291.26.10^{3}(2.15)[/tex]
[tex]F_{r}=[/tex] 626209 N or 626.2 kN
At the cylindrical tank's flat bottom, net force has magnitude 626.2 kN.
6. Balsa wood with an average density of 130 kg/m3 is floating in pure water. What percentage of the wood is submerged
Answer:
The percentage of the submerged wood is 13%.
Explanation:
Given;
density of the Balsa wood, [tex]\rho _{wood}[/tex] = 130 kg/m³
density of pure water, [tex]\rho_{water}[/tex] = 1000 kg/m³
The percentage of the submerged wood is calculated as;
[tex]Percentage \ of \ submerged \ wood = \frac{130 \ kg/m^3}{1000 \ kg/m^3} \ \times \ 100 \% \\\\Percentage \ of \ submerged \ wood = 13 \ \%[/tex]
Therefore, the percentage of the submerged wood is 13%.
What's the effect of mass and speed on kinetic energy
Answer:
The relationship between Kinetic energy, mass and speed indicates that kinetic energy and mass are proportional. This proportionality implies that if the mass is doubled, its kinetic energy is doubled too. More generally, if two objects move with the same speed the most massive one has the higher kinetic energy
Explanation:
Calculate the momentum of a 1,500 kg car traveling at 6 m/s.
A military airplane sometimes needs to refuel in mid-air, and another plane flies above it to add the fuel. If a plane with a mass of 7,800 kg is traveling with a velocity of 30 m/s and refuels by adding an additional 800 kg of jet fuel, what will its new velocity be? (Hint: This is a multi-step problem).
Answer:
See the answers below.
Explanation:
Momentum is defined as the product of mass by velocity, in this way we have the following equation.
[tex]P=m*v[/tex]
where:
P = momemtum [kg*m/s]
m = mass = 1500 [kg]
v = velocity = 6 [m/s]
[tex]P = 1500*6\\P=9000 [kg*m/s][/tex]
Now we have to calculate the momentum of the plane when it travels at 30 [m/s].
[tex]P_{airplane}=m_{plane}*v_{plane}\\P_{airplane}=7800*30\\P_{airplane}=234000[kg*m/s][/tex]
Now this same momentum must be conserved, in such a way that the mass is increased but the velocity must decrease for the momentum to be conserved.
[tex]P=m_{new}*v_{new}\\234000=(7800+800)*v_{new}\\234000=8600*v_{new}\\v_{new}=27.2[m/s][/tex]
Answer:
1. 9000 kg-m/s
2. 27.2 m/s
A soccer player kicks a soccer ball (m = 0.42 kg) accelerating from rest to 32.5m/s in 0.21s. Determine the force that sends soccer ball towards the goal.
Help:(
Answer:
65 N
Explanation:
m = Mass of ball = 0.42 kg
u = Initial velocity = 0
v = Final velocity = 32.5 m/s
a = Acceleration = [tex]\dfrac{v-u}{t}[/tex]
t = Time = 0.21 s
Force is given by
[tex]F=ma[/tex]
[tex]\Rightarrow F=m\dfrac{v-u}{t}[/tex]
[tex]\Rightarrow F=0.42\times \dfrac{32.5-0}{0.21}[/tex]
[tex]\Rightarrow F=65\ \text{N}[/tex]
The force that sends soccer ball towards the goal is 65 N.
A ray of light is incident from air into diamond at the surface with an angle of 70 degree. what is the angle it makes in the diamond if the refraction index of diamond is 2.42.
Answer: Angle is 18.66°
Explanation: When an incident light passes through two different media, the ray of light is refracted. Refraction is the bending of the light that happens when the wave changes its velocity while passing through a different surface.
The incident light makes an angle with the normal to the surface at a point. This angle is called Angle of Incidence. After going through the other medium, the wave makes a different angle with the normal. That angle is called Angle of Refraction.
Light changes velocity when passing through different media because each material has different index of refraction. For air, index of refraction is n = 1.
The incident angle, the refracted angle and index of refraction is related by the following formula, known as Snell's Law:
[tex]n_{1}sin\theta_{1}=n_{2}sin\theta_{2}[/tex]
where
n₁ is index of refraction of the incident medium
θ₁ is angle of incidence
n₂ is index of refration of the refracted medium
θ₂ is angle of refraction
For the ray of light incident from air into a diamond, the angle of refraction is
[tex]sin\theta_{2}=\frac{n_{1}sin\theta_{1}}{n_{2}}[/tex]
[tex]sin\theta_{2}=\frac{1*sin70}{2.42}[/tex]
[tex]sin\theta_{2}=0.32[/tex]
[tex]\theta_{2}=arcsin 0.32[/tex]
[tex]\theta_{2}=[/tex] 18.66
The angle light makes in the diamond is 18.66°.
