Answer:
90 m
Explanation:
For ball A::
The equation of a ball moving upwards is given by the formula:
s = ut - (1/2)gt²
where u is the initial velocity, t is the time covered, g is the acceleration due to gravity = 10 m/s² and s is the distance travelled.
Given that:
u = 10 m/s, t = 3 sec, g = 10 m/s², hence:
s = (10 * 3) - (1/2) * 10 * 3²
s = 30 - 45
s = -15 m
The negative sign means the object travels in the opposite direction. Hence s = 15 m
For ball B::
The equation of a ball falling downwards is given by the formula:
s = ut + (1/2)gt²
Given that:
u = 10 m/s, t = 3 sec, g = 10 m/s², hence:
s = (10 * 3) + (1/2) * 10 * 3²
s = 30 + 45
s = 75 m
Hence the separation between the two balls after 3 sec of projection = 15 m + 75 m = 90 m
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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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]
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
A force of 6.7 N acts on a 30 kg body initially at rest. Compute the work done by the force in (a) the first, (b) the second, and (c) the third seconds and (d) the instantaneous power due to the force at the end of the third second.
Answer:
(a) 0.748 J
(b) 2.245 J
(c) 3.74 J
(d) 4.482 W
Explanation:
(a) Work done W = Force × distance
W = F×d,
Where d = 1/2(at²)
Therefore,
W =1/2(F×at²)................ Equation 1
Where a = acceleration, t = time.
But,
a = F/m...................... Equation 2
Where m = mass.
Substitute equation 1 into equation 2
W = 1/2(F²t²/m)................. Equation 3
Given: F = 6.7 N, t = 1 s, m = 30 kg
Substitute into equation 3
W₁ = 1/2(6.7²×1²/30)
W = 0.748 J.
(b) Similarly,
The work done in the second seconds is
Where t₂ = 2 s
W₂ = 1/2(F²t₂²/m)- W₁
W = 1/2(6.7²×2²/30)-0.748
W = 2.245 J
(c) The work done in the third seconds is
Where t₃ = 3 s
W₃ = 1/2(F²t₃²/m)-(W₂+W₃)
W = 1/2(6.7²×3²/30)-(2.993)
W = 3.74 J.
(d) P = Fv ............... Equation 4
Where v = velocity.
and,
v = at..................... Equation 5
Substitute equation 5 into equation 4
P = Fat................... Equation 6
Given: F = 6.7 N, a = 6.7/30 = 0.223 m/s², t = 3 s
Substitute into equation 6
P = 6.7×0.223×3
P = 4.482 W.
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°.
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!
hii Happy New year can you all please answer this
Answer:
truuuuuuuuuuuuueeeeeeeee
A population’s exponential growth is the number of offspring produced over a given time period.True or false
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
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:
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.
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:
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:
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:
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%.
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:
A roller coaster car accelerates uniformly covers a distance of 50 m while increasing its speed
from 5.0 m/s to 25 m/s. How long does it take for this to occur? What is its average velocity over
this distance? (3.3 s. 15 m/s)
Proof please
Answer:
Explanation:
Given parameters:
Distance covered = 50m
Initial velocity = 5m/s
Final velocity = 25m/s
Unknown:
Time taken to cover the distance = ?
Average velocity = ?
Solution:
To solve this problem, we use the expression below:
x = [tex](\frac{v + u}{2}) t[/tex]
x is the distance
v is the final velocity
u is the initial velocity
t is the time
50 = [tex]\frac{5 + 25}{2}[/tex] x t
50 = 15 x t
t = 3.3s
Average velocity = [tex]\frac{v + u}{2}[/tex] = [tex]\frac{5+25}{2}[/tex] = 15m/s
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.
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
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
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 .
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
A woman lives on the eighth floor of an apartment building. She works in a high-rise office building 6.5 blocks away from her apartment on the same street. Her office is on the 14th floor. Assume each story of her apartment building is 4.0 m, each story of her office building is 5.5 m, and a block is 146.6 m long.
Required:
a. Sketch her path.
b. Estimate the distance she travels to work.
c. Find the magnitude of her displacement.
Answer:
b) d = 997.9 m , c) D = (952.9 i ^ +45 k ^) m , D = 953.6 m and θ = 2.7º
Explanation:
In this exercise we must add the distance traveled, remembering that the displacement is a vector and the distance a scalar.
a) The displacement scheme is the woman walks in her building A to descend to the lower floor 4.0 m, we assume that this includes the vertical displacement, until reaching the street level, the displacement is vertical in this part.
Being on the street, she travels the 6.5 blocks to reach the building where she works, they indicate that each block is 146.6 m, this movement is horizontal.
Upon reaching building B, she goes up to his office on the 14th floor where she travels 5.5m on each floor, it is assumed that the distance to go up to the upper floor is included, this displacement is vertical
b and c) Let's find the distance traveled and the displacement
in building A
Zₐ = 8 * 4.0
Zₐ = -32.0 m k ^
the vector k ^ indicates that the displacement is vertical and the negative sign that it is descending
on the street
[tex]X_{ab}[/tex] = 6.5 146.6
X_{ab} = 952.9 m i ^
the vector i ^ indicates that the displacement is the x-axis, we assume that the axis is in the direction of the displacement
in building B
[tex]Z_{b}[/tex] = 14 * 5.5
Z_{b} = 77 m k ^
displacement in the vertical axis and in the positive direction
now we calculate the distance traveled,
d = Zₐ + X_{ab} + Z_{b}
d = -32 + 952.9 + 77
d = 997.9 m
note that this value is a scalar
Let's calculate the displacement,
Z axis
[tex]Z_{total}[/tex] = Zₐ + Z_{b}
Z_{total} = -32 + 77
Z_{total} = 45 m k ^
X axis
X_{total} = X_{ab}
X_{total} = 952.9 m i ^
we can give the result in two ways
a) D = X_total i ^ + Z_total k ^
D = (952.9 i ^ +45 k ^) m
b) in module form and angles
Let's use the Pythagorean theorem
D² = [tex]X_{total}^2[/tex] + [tex]Z_{total}^2[/tex]
D = √(952.9² + 45²)
D = 953.6 m
We use trigonometry
tan θ = Z / X
θ = tan⁻¹ (Z / X)
θ = tan⁻¹ (45 / 952.9)
θ = 2.7º
this angle is measured from the positive side of the x axis towards the z axis
who was the first president of America
Answer:George Washington
Explanation:On April 30, 1789, George Washington, standing on the balcony of Federal Hall on Wall Street in New York, took his oath of office as the first President of the United States.
Answer:
George Washington
Explanation:
Hope this helps out
what is mechanics physics
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.
Plis I need Help:(
Answer:
F=65 N
Explanation:
Uniform Acceleration
When an object changes its velocity at the same rate, the acceleration is constant.
The relation between the initial and final speeds is:
[tex]v_f=v_o+a.t[/tex]
Solving for a:
[tex]\displaystyle a=\frac{v_f-v_o}{t}[/tex]
Where:
vf = Final speed
vo = Initial speed
a = Constant acceleration
t = Elapsed time
The ball is kicked from rest vo=0 to vf=32.5 m/s in t=0.21 s. Computing the acceleration:
[tex]\displaystyle a=\frac{32.5-0}{0.21}[/tex]
[tex]a=154.8\ m/s^2[/tex]
Note: We have shown this result rounded to the nearest tenth, but we kept all the decimals in a scientific calculator for further calculations.
The force needed to accelerate the soccer ball is calculated by:
F = ma
The ball has a mass of m=0.42 kg, thus:
F=0.42*154.8
F=65 N
As mentioned, this result can only be obtained by keeping full precision in the above calculations.
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 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
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.
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.
