Seasonal change in the angle of sunlight, caused by the tilt of the Earth's axis, is the basic mechanism that results both in warmth of the weather and in length of the day.
A beaker is filled with water. A small plastic container contains a solid bar of aluminum, which has a mass of 40 g, and is placed on the water so that it floats. The water level reads 60 ml. Next, the bar of aluminum is taken out of the container and placed in the water so that it sinks to the bottom. By how much does the water level change?
Answer:
25.2 ml
Explanation:
When the aluminium block is inserted in the container, the overall amount of only the water in the beaker can equal V o.
The weight of the water expelled by the plastic container should be equal to the weight of the aluminium block, according to the buoyancy balance relation.
i.e.
[tex]\rho_w V_wg = m_{Al}g = \rho_{Al}V_{Al} g \\ \\ V_w = \dfrac{\rho_{Al}V_{AL}}{\rho_{w}}[/tex]
When the aluminium block is inserted into the plastic container, the initial volume of water = 60 ml
[tex]V_i = V_o + V_w[/tex]
[tex]V_i = V_o + \dfrac{\rho_{Al}V_{Al}}{\rho_{w}}---(1)[/tex]
When the aluminium block is placed outside the container, the volume of the water
[tex]V_f = V_o +V_{Al} ---(2)[/tex]
By subtracting equation (1) and (2)
[tex]V_i -V_f = V_o + \dfrac{\rho_{Al} V_{Al}}{\rho_w}- ( V_o + V_{Al}}) \\ \\ =\dfrac{\rho _{Al}V_{Al}}{\rho_w}-V_{Al} \\ \\ = V_{Al} \Big( \dfrac{\rho_{Al}}{\rho_{w}}-1 \Big)[/tex]
since;
[tex]m_{Al} = 40 g[/tex]
[tex]V _{Al} = \dfrac{40 \ g}{2.7 \ g/cm^3} \\ \\ V_{Al} = 14.815 \ cm^3[/tex]
Similarly;
[tex]\dfrac{\rho_{Al}}{\rho_{w}}= \dfrac{2.7 }{1.0}[/tex]
= 2.7
[tex]V_i -V_f =14.815\Big( 2.7-1 \Big) \\ \\ V_i -V_f = 25.1855 \ ml \\ \\ = \mathbf{25.2 \ ml}[/tex]
A typical electric refrigerator has a power rating of 500 Watts, which is the rate (J/s) at which electrical energy is supplied to do work needed to remove heat from the refrigerator. If the refrigerator releases heat to the room at a rate of 800 Watts, at what rate (in Watts) does it remove heat from inside of the refrigerator?
Answer:
The rate of heat removed from inside the refrigerator is 300 watts.
Explanation:
By the First Law of Thermodynamics and the definition of a Refrigeration Cycle, we have the following formula to determine the rate of heat removed from inside the refrigerator ([tex]\dot Q_{L}[/tex]), in watts:
[tex]\dot Q_{L} = \dot Q_{H}-\dot W[/tex] (1)
Where:
[tex]\dot Q_{H}[/tex] - Rate of heat released to the room, in watts.
[tex]\dot W[/tex] - Rate of electric energy needed by the refrigerator, in watts.
If we know that [tex]\dot Q_{H} = 800\,W[/tex] and [tex]\dot W = 500\,W[/tex], then the rate of heat removed from inside the refrigerator is:
[tex]\dot Q_{L} = \dot Q_{H}-\dot W[/tex]
[tex]\dot Q_{L} = 300\,W[/tex]
The rate of heat removed from inside the refrigerator is 300 watts.
a man hikes 6.6 km north along a straight path with an average velocity of 4.2 km/h to the north. he rest at a bench for 15 min. then, he hikes 3.8 km birth with an average velocity of 5.1 km/h to the north. how long does it take the total hike to last
Answer:
2.6h
Explanation:
I attached the image below of the work hope you can see it. Hope this helps!
Man takes approximately 2.56 hr to hike to last.
What is average velocity ?
Average velocity is given by the total distance covered by the object in total given time.
here, to calculate total time "t" taken by the man to hike at last it will be equals to the sum of the time "t₁" taken to travel 6.6km, time "t₂" he had taken rest and time "t₃" he had taken to travel 3.8 km.
Therefore, total time t is calculated :
[tex]\begin{aligned}t&=t_{1}+t_{2}+t_{3}\\&=\frac{6.6}{4.2}+\frac{15}{60}+\frac{3.8}{5.1}\\&\approx 2.56 \text{\:h}\end{aligned}[/tex]
Thus the man takes approximately 2.56 hr to hike to last.
Learn more about "average velocity" here:
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the electrostatic force between two objects is 40N. if the charge of one object is cut in half, and the distance is doubled, what is the new force?
Answer:
F1 = K Q1 Q2 / R1^2
F2 = K Q1 / 2 * Q2 / (2 R1)^2
F2 / F1 = 1/2 / 4 = 1/8
The new force is 5N (1/2 due to charge and 1/4 due to distance)
Wind power is considered a renewable energy source.
O True
O False
Answer:
True
Explanation:
Answer:
your answer is true hope this helps
What is the typical treatment for Hodgkin's disease?
desensitization treatments, bone marrow transplant, and biopsy
desensitization treatments, chemotherapy, and thymectomy
radiation, biopsy, and desensitization treatments
radiation, chemotherapy, and bone marrow transplant
Answer:
Pretty sure its D.
radiation, chemotherapy, and bone marrow transplant
Explanation:
Radiation, chemotherapy, and bone marrow transplant are the typical treatment for Hodgkin's disease. Therefore, option (D) is correct.
What is Hodgkin lymphoma?Hodgkin lymphoma can be described as a type of lymphoma, in which cancer forms from a specific type of white blood cell known as lymphocytes, where multinucleated Reed-Sternberg cells are present in the lymph nodes.
The most common symptom of Hodgkin's lymphoma is the painless enlargement of lymph nodes. Hodgkin lymphoma can be treated with radiation therapy, chemotherapy, and stem cell transplantation. The treatment generally depends on how advanced cancer has favorable features.
Radiation and chemotherapy drugs increase the risk of other cancers, lung disease, or heart disease over the subsequent decades.
Hodgkin lymphoma can be distinguished from non-cancerous causes of lymph node swelling and from other cancer. Definitive diagnosis is by lymph node biopsy. Blood tests are performed to assess the function of major organs and safety for chemotherapy.
Learn more about Hodgkin lymphoma, here:
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How do you make camping fun?
B
С
17. A car moves at constant speed of 40 kmh-' along the
road shown in Fig. 17.1. The radius of curvature at
A is 350 m and the total acceleration of the car at B is
1.0 ms?
(a) Find the total acceleration of the car at
A
5 p
5
Fig. 17.1
[2]
i. A
[1]
ii. C
2
(b) Find the radius of curvature at B.
Answer:
a
Explanation:
a
1. There are 15 boys and girls 25 in Grade VI- Jacinto . Name the ratio of girls to boys in
fractional form?
A. 15/20
B. 15/25
C. 20/25
D. 25230
A ball is rolling away from you at a constant speed, hits a wall, and then suddenly stops moving. Imagine a position-versus-time graph showing the ball’s motion. Describe the line on the graph.
Answer:
It would show a "straight line".
Explanation:
Newton's First Law of Motion states that an object at rest will remain at rest and an object in motion will remain in motion (at a constant velocity) unless acted upon by an unbalanced force. Newton's first law of motion is also called the law of inertia.
money is rare? or is it bad
Answer:
money is not rare. you can find it everywhere. what exactly is the question? whether it is bad or not is an opinion.
Explanation:
5. What do depression and asthma have in common?
a. Both are mood disorders
b. Both affect the same organs
c. Both have similar symptoms
d. Both can be treated
Answer:
a. Both are mood disorders
Explanation:
Depression and asthma are common comorbid diseases and mood disorders in patients with asthma are associated with poor asthma outcomes such as decreased lung function, more frequent emergency department visits and reduced quality of life
What is the change in internal energy if 30 J of heat are released from a
system and the system does 50 J of work on its surroundings?
Use AU= Q-W.
Answer:
Option B. –80 J
Explanation:
From the question given above, the following data were obtained:
Heat (Q) released = –30 J (negative sign because the heat is being released to the surrounding)
Work (W) = 50 J
Change in internal energy (ΔU) =?
We can obtain the change in the internal energy as follow:
ΔU = Q – W
ΔU = –30 – 50
ΔU = –80 J
Therefore, the change in the internal energy is –80 J
Thus, option B gives the correct answer to the question.
Jupiter's Great Red Spot is
1.slowly shrinking
2.a large storm
3.smaller than Saturn's spot
4.a large area of liquid hydrogen
Answer:
2 : A large storm
Explanation: I hope this helps
A long conducting cylinder of radius a carrying a total charge +q is surrounded by a
concentric thin conducting cylindrical shell of radius b carrying a total charge -2q.
Draw the cross section of this arrangement. Use Gauss’s law to find the electric field
strength at a point r away from the axis,
Answer:
I don't know this, sorry
why is it important to observe safety rules in food preservation?
pls help
Answer:
Yes it is important.
Explanation:
It is important because we should preserve our food with safety as we would take it in the next day so if we we will not take safety then many germs can enter in that food and if we eat that food we could get sick . If we keep the food uncovered so anything can happen like any insect can fall in the food and we didn't know it it or any germs can enter in the food that is very harmful for our body so so we should keep the food covered and well preserved.
A string with a length of 6.2 m is vibrated at its natural frequency (first harmonic). What is the wavelength of the produced standing wave?
3.1 m
6.2 m
12.4 m
18.6 m
Answer:
12.4m
Explanation:
Given
Length of string = 6.2m
L = λ/2 (for natural frequency (first harmonic)
λ = 2L
λ = 2(6.2)
λ = 12.4m
Hence the wavelength of the produced standing wave is 12.4m
A car of mass, 1200 kg is pulled with constant force of 3000N in 20s. Work out A) The acceleration resulted: B) Distance travelled by the car, in the given time? C) Work done by the engine of the car D) The kinetic energy of the Car
Answer:
D
Explanation:
the energy is coming up and down
The answer is:
D) The kinetic energy of the car
Which of the following is not a characteristic of electrical potential energy?
Answer:
It is a form of mechanical energy
Explanation:
A box is moved 10 m across a smooth floor by a force F making a downward angle with the floor, so that there is effectively a 4 N force acting parallel to the floor in the direction of motion and a 3 N force acting perpendicular to the floor. The force F acts for 20 seconds. The impulse delivered to the box by the floor during this process has magnitude
Answer:
Zero
Explanation:
Impulse is defined as the change in momentum.
Impulse is also defined as the product of force and the time duration of application of the force.
In the given problem, since there is no motion in the vertical direction, therefore the velocity of the box along the vertical direction is zero. So, momentum of the box along the vertical is also zero.
Hence the change is momentum is also zero along vertical direction.
Thus the impulse delivered by the box is zero.
Ajani is trying to experimentally measure Planck's constant h. He does this by shining different wavelengths of monochro- matic (i.e., single-wavelength) EM radiation on a metal plate with unknown work function W, and then measuring the stop- ping voltage required to bring the ejected electrons to a halt. When he uses λ1= 400 nm, he finds that a stopping voltage of V1 = 0.7 V is required. When he uses λ2 = 500 nm, he finds that a stopping voltage of V2= 0.2 V is required. Based on these two data points, what is Ajani's measurement of Planck's constant?
Answer:
h = 1.01 x 10⁻³⁴ J.s
Explanation:
The energy applied by the voltage must be equal to the energy associated with the wavelength of light:
[tex]eV = \frac{hc}{\lambda}\\[/tex]
where,
e = charge on electron = 1.6 x 10⁻¹⁹ C
V = stopping potential
h = Planck's Constant = ?
c = speed of light = 3 x 10⁸ m/s
λ = wavelength of light
For λ = 400 nm = 4 x 10⁻⁷ m, V = 0.7 V:
[tex](1.6\ x\ 10^{-19}\ C)(0.7\ V) = \frac{h(3\ x\ 10^8\ m/s)}{4\ x\ 10^{-7}\ m}\\[/tex]
h = 1.49 x 10⁻³⁴ J.s
For λ = 500 nm = 5 x 10⁻⁷ m, V = 0.2 V:
[tex](1.6\ x\ 10^{-19}\ C)(0.2\ V) = \frac{h(3\ x\ 10^8\ m/s)}{5\ x\ 10^{-7}\ m}\\[/tex]
h = 0.53 x 10⁻³⁴ J.s
Taking average of both values:
[tex]h = \frac{(0.53+1.49)\ x\ 10^{-19}\ J.s}{2}[/tex]
h = 1.01 x 10⁻³⁴ J.s
How efficient are the small and large scale solar-power systems used in individual homes and industrial settings?
Plz someone help me
Answer:
I study physics too, want me to study with you?
1. Which energy is stored in the bonds between atoms?
Answer:
Explanation: Energy, potential energy, is stored in the covalent bonds holding atoms together in the form of molecules. This is often called chemical energy.
Calculate the height of a cliff if it takes 2.35s for a rock to hit the ground when it is thrown straight up from the cliff with a initial velocity 8m/s.
Answer:
y₀ = 10.625 m
Explanation:
For this exercise we will use the kinematic relations, where the upward direction is positive.
y = y₀ + v₀ t - ½ g t²
in the exercise they indicate the initial velocity v₀ = 8 m / s.
when the rock reaches the ground its height is zero
0 = y₀ + v₀ t - ½ g t²
y₀i = -v₀ t + ½ g t²
let's calculate
y₀ = - 8 2.5 + ½ 9.8 2.5²
y₀ = 10.625 m
who invented physics?
Answer:
I think Albert Einstein invented physics.
Explanation:
Iam soory if Iam wrong.
how do you define teaching?
Answer:
Teaching is the process of attending to people's needs, experiences and feelings, and making specific interventions to help them learn particular things.
Explanation:
Hope it helps✌Answer:
In education, teaching is the concerted sharing of knowledge and experience, which is usually organized within a discipline and, more generally, the provision of stimulus to the psychological and intellectual growth of a person by another person or artifact.
what is magnetic flux thru a closed surface
Answer: Zero
Explanation:
Gauss's law states that the total magnetic flux through a closed surface is equal to zero. Because the magnetic field lines are in continuous loops, so all closed surfaces have magnetic field lines coming out, hence the net magnetic flux is zero.
Roland Incorporated manufactures and sells portable hair dryers. If the price of a hair dryer is $ 127.00, then the company sells 116 hair dryers per week, and the elasticity of demand is −0.463. Assume that the demand function is differentiable and that the only time the company sells exactly 116 hair dryers per week is when the price of a hair dryer is $ 127.00. Given this situation, which of the following do you know MUST be true?
a. The marginal revenue is negative when Roland sells 144 driers per week.
b. The marginal profit is negative when Roland sells 144 driers per week.
c. The marginal profit is positive when Roland sells 144 driers per week.
d. The marginal revenue is positive when Roland sells 144 driers per week.
Answer:
The marginal revenue is positive when Roland sells 144 driers per week ( D
Explanation:
Elasticity of demand = -0.463
P = $127
116 hair dryers sold per week ( q )
demand function is differentiable
prove the true statement below
Revenue = price per unit * quantity
determine the Marginal revenue = dr / dq
∴ MR = P + q dp/dq
price elasticity of demand E(p) = - dq / dp * p/q
where : E ( p ) = - 0.463 , q = 116 , p = $127
q * dp/dq = P / 0.463
∴ MR = P * 1.463 / 0.463
= 127 * 3.16 = $401.32
since the Marginal revenue > 0 HENCE The marginal revenue will be positive when Roland sells 144 driers per week.
A water pipe having a 4.00 cm inside diameter carries water into the basement of a house at a speed of 1.00 m/s and a pressure of 167 kPa. The pipe tapers to 1.4 cm and rises to the second floor 7.8 m above the input point. What is the speed at the second floor
Answer:
[tex]8.16\ \text{m/s}[/tex]
Explanation:
[tex]d_1[/tex] = Initial diameter = 4 cm
[tex]v_1[/tex] = Initial velocity = 1 m/s
[tex]d_2[/tex] = Final diameter = 7.8 m
[tex]v_2[/tex] = Final velocity
[tex]A[/tex] = Area = [tex]\pi\dfrac{d^2}{4}[/tex]
From the continuity equation we get
[tex]A_1v_1=A_2v_2\\\Rightarrow \pi\dfrac{d_1^2}{4}v_1=\pi\dfrac{d_2^2}{4}v_2\\\Rightarrow v_2=\dfrac{d_1^2}{d_2^2}v_1\\\Rightarrow v_2=\dfrac{4^2}{1.4^2}\times 1\\\Rightarrow v_2=8.16\ \text{m/s}[/tex]
The speed of water at the second floor is [tex]8.16\ \text{m/s}[/tex].
18-A tire rotates at a constant 1.7 radians angle every 0.15 s. A) What is the tire's angular 2 points
velocity? B) If the tire has a diameter of tire is 70 cm, what is the linear speed of the car?*
Explanation:
A) use the formula:
[tex]angular \: velocity = angular \: dispacement \div time[/tex]
B) use the formula:
[tex]linear \: velocity = radius \times angular \: velocity[/tex]
with angular velocity u calculated in A)