Answer:
714.286g
Explanation:
Q=mcT
60000=m×4.2×(40-20)
m=714.285....g
A normal person consumes 2000 food calories a day. If a food calorie is equivalent to 4200 J of energy, use reasonable assumptions to calculate the number of kilograms of water that can be boiled away to steam starting from 20o C
Answer:
The mass of water boiled away as steam is 3.24 kg
Explanation:
Given;
total food calories consumed, 2000
1 calorie = 4,200 J
total energy of food consumed in joules, Q = 2,000 x 4,200 J = 8,400,000 J
initial temperature of the water, t₁ = 20 ⁰C
Assumptions:
(1) No energy is lost
(2) all the water is boiled to steam
(3) Energy needed to raise water to 100 ⁰C (q₁) plus Energy needed to boil the water to steam (q₂) = total energy of food consumed (Q)
(4) latent heat of vaporization of water, L = 2,260 kJ/kg
(5) specific heat capacity of water, c = 4,200 J/kg⁰C
let the mass of the water = m
Q = q₁ + q₂
Q = mcΔt + mL
Q = mc(t₂ - t₁) + mL
8,400,000 = 4,200(100 - 20)m + 2,260,000m
8,400,000 = 336,000m + 2,260,000m
8,400,000 = 2,596,000 m
m = 8,400,000/2,596,000
m = 3.24 kg
Therefore, the mass of water boiled away as steam is 3.24 kg
What do different forms of energy have in common?
A. They can push or pull on objects.
B. They give objects mass.
C. They can cause changes in matter.
D. They can cause objects to move.
Answer:
C because it changes your energy
At an amusement park, a 7.00 kg swimmer uses a water slide to enter the main pool. The swimmer starts at rest, slides without friction, and descends through a vertical height of 0.40 m. Find the total energy present when the swimmer is at the top of the slide.
Answer:
27.44 J
Explanation:
We can find the energy at the top of the slide by using the potential energy equation:
PE = mghAt the top of the slide, the swimmer has 0 kinetic energy and maximum potential energy.
The swimmer's mass is given as 7.00 kg.
The acceleration due to gravity is 9.8 m/s².
The (vertical) height of the water slide is 0.40 m.
Substitute these values into the potential energy equation:
PE = (7.00)(9.8)(0.40) PE = 27.44Since there is 0 kinetic energy at the top of the slide, the total energy present is the swimmer's potential energy.
Therefore, the answer is 27.44 J of energy when the swimmer is at the top of the slide.
a stone is thrown vertically upward with an initial velocity of 14m/sc negleting in air resistance find (a)Maximum height reached and (b)Time taken before it reached the ground
Answer:
1/2 m v^2 = m g H conservation of energy
H = (v^2 / (2 * g))^1/2 = (14^2 / 19.6)^1/2 = 10 m
H = 1/2 g t^2 time to fall 10 m
t = (2 * H / g)^1/2 = (20 / 9.8)^1/2 = 1.43 sec
Total time in air = 2 * 1.43 = 2.86
You can also use 2 a S = V0^2 since final velocity = 1.43 * 9.8 m/s = 14 m / s
and 2 a S = 2 * 9.8 * 10 = 196 m^2 / s^2 which is V0 squared
Two blocks A and B with mA = 2.9 kg and mB = 0.87 kg are connected by a string of negligible mass. They rest on a frictionless horizontal surface. You pull on block A with a horizontal force of 6 N. Determine the tension in the string connecting the two blocks.
Answer:
Tension = 1.38 N
Explanation:
Given that:
Mass of block A [tex]m_A[/tex] = 2.9 kg
mass of block B [tex]m_B[/tex] = 0.87 kg
Force F = 6 N
Assume a = acceleration of the blocks.
Then:
[tex]m_A[/tex] (a) + [tex]m_B[/tex] (a) = 6
2.9a + 0.87a = 6
3.77a = 6
a = 6/3.77
a = 1.59 m/s²
Suppose T to be the tension in the string.
If we take a look at the forces acting on the first block, then:
F - T = [tex]m_A[/tex] (a)
T = F - [tex]m_A[/tex] (a)
T = 6 - 2.9(1.59)
T = 6 - 4.62
T = 1.38 N
Determine the work done by the constant force. The locomotive of a freight train pulls its cars with a constant force of 15 tons a distance of one-quarter mile.
Answer:
5.92×10⁷ J
Explanation:
We'll begin by converting 15 tons to Newton. This can be obtained as follow:
1 ton = 9806.65 N
Therefore,
15 ton = 15 ton × 9806.65 N / 1 ton
15 ton = 147099.75 N
Next, we shall convert one-quarter (¼) or 0.25 mile to metre. This can be obtained as follow:
100 mi = 160934 m
0.25 mi = 0.25 mi × 160934 / 100 mi
0.25 mi = 402.335 m
Finally, we shall determine the Workdone. This can be obtained as follow:
Force (F) = 147099.75 N
Distance (d) = 402.335 m
Workdone (Wd) =?
Wd = F × d
Wd = 147099.75 × 402.335
Wd = 5.92×10⁷ J
Thus, the Workdone is 5.92×10⁷ J
Which of the following never cause a change in the motion of an object? A. Net forces B. Unbalanced forces O C. Balanced forces O D. Contact forces
Answer:
balanced force never changes its motion
A ball is spun around in circular motion such that its frequency is 10 Hz.
a. What is the period of its rotation?
b. How much time will be required to complete 100 rotations?
Answer:
a = 0.1 s b. 10 s
Explanation:
Given that,
The frequency in circular motion, f = 10 Hz
(a) Let T is the period of itsrotation. We know that,
T = 1/f
So,
T = 1/10
= 0.1 s
(b) Frequency is number of rotations per unit time. So,
[tex]t=\dfrac{n}{f}\\\\t=\dfrac{100}{10}\\\\t=10\ s[/tex]
Hence, this is the required solution.
Two objects (42.0 and 21.0 kg) are connected by a massless string that passes over a massless, frictionless pulley. The pulley hangs from the ceiling. Find (a) the acceleration of the objects and (b) the tension in the string.
Answer:
a = 3.27 m/s²
T = 275 N
Explanation:
Given that:
Mass m₁ = 42.p0 kg
Mass m₂ = 21.0 kg
Consider both masses to be in a whole system, then:
The acceleration can be determined as:
[tex](m_1+m_2)a = g(m_1-m_2)[/tex]
Making acceleration the subject in the above formula;
[tex]a =\dfrac{g(m_1-m_2)}{(m_1+m_2)}[/tex]
[tex]a =\dfrac{9.8(42.0-21.0)}{(42.0+21.0)}[/tex]
[tex]a =\dfrac{9.8(21.0)}{(63.0)}[/tex]
[tex]a =\dfrac{205.8}{(63.0)}[/tex]
a = 3.27 m/s²
in the string, the tension is calculated using the formula:
[tex]T = \dfrac{2m_1m_2g}{(m_1+m_2)}[/tex]
[tex]T = \dfrac{2(42)(21)(9.81)}{(42+21)}[/tex]
[tex]T = \dfrac{17304.84}{63}[/tex]
T = 274.68 N
T ≅ 275 N
Light with some unknown wavelength is incident on a piece of copper. The most energetic electrons emitted from the copper have 2.7 eV of kinetic energy. If the copper is replaced with a piece of sodium, what will be the maximum possible kinetic energy K of the electrons emitted from this new surface
This question is in complete, the missing table is uploaded along this answer.
Answer:
the maximum possible kinetic energy K of the electrons emitted from this new surface is 4.9 eV
Explanation:
Given the data in the question;
copper K = 2.7 eV
If the copper is replaced with a piece of sodium ( Na )
the maximum possible kinetic energy K of the electrons emitted from this new surface = ?
we know that;
Kinetic energy of emitted electrons can be written as;
K = hv - hv₀
where v is frequency, h is Plank's constant, and hv₀ is work function of metal
so lets make hv the subject of formula;
hv = K + hv₀
from the table below, work function of copper is 4.5 eV
so we substitute
hv = 2.7 eV + 4.5 eV
hv = 7.2 eV
Now, If the copper is replaced with a piece of sodium ( Na )
we have;
K = hv - hv₀
from the table below, work function of Sodium is 2.3 eV
so we substitute
K = 7.2 eV - 2.3 eV
K = 4.9 eV
Therefore, the maximum possible kinetic energy K of the electrons emitted from this new surface is 4.9 eV
A bicyclist rides 1.59 km due east, while the resistive force from the air has a magnitude of 7.00 N and points due west. The rider then turns around and rides 1.59 km due west, back to her starting point. The resistive force from the air on the return trip has a magnitude of 7.00 N and points due east. Find the work done by the resistive force during the round trip. Number Units
Answer:
The required work done by the resistive force = -22.3 kJ
Explanation:
We understand that the amount of work done for a force F and displacements is provided as the product of force multiplied by displacement, which can be represented as W = F.S
Now, when the cyclist travels east and returns west, the force and displacement directions will be opposite and they make an angle 180 degrees apart.
∴
W = -2 × 7.00 × 1590
W = -22260 J
W = -22.3 kJ
A point charge Q at the center of a sphere of radius R produces an electric flux of Φ coming out of the sphere. If the charge remains the same but the radius of the sphere is doubled, the electric flux coming out of it will be
Remains the same
Explanation:
According to Gauss's law, the electric flux through a closed surface is proportional to the charge enclosed by the surface. So no matter how big or small we make the surface that encloses the charge, the electric flux remains the same because it only depends on the enclosed charge, not surface area.
Two students are debating about the nature of light:a.Student 1: Looking at the chart, I see that light with a shorter wavelength has the highest frequency. But all light has the same speed.b.Student 2: I disagree with your Student 1. If light has a higher frequency, then it will have a faster speed than light with a lower energy.
Answer:
student 1 is right and student 2 is wrong
Explanation:
In the graph that the two students are observing is a graph of energy and frequency vs. wavelength, this graph is constructed using the relationship between a wave and its wavelength and frequency.
c = λ f
therefore for all waves we have the speed salami.
Therefore student 1 is right and student 2 is wrong
Monochromatic light passes through two slits separated by distance of 0.03 mm. Calculate the wavelength of the light if the angle from the centre fringe to the third maximum is 3°.
Answer:
I love you...I Miss u and love you too...I miss my mom
Which nucleus completes the following equation?
Answer:
Option D. ²⁰⁸₈₄Po
Explanation:
From the question given above, the following data were obtained:
²¹²₈₆Rn —> ⁴₂He + ?
Let the unknown be ⁿₓD. Thus, the equation becomes:
²¹²₈₆Rn —> ⁴₂He + ⁿₓD
Next, we shall determine n, x and D. This can be obtained as follow:
212 = 4 + n
Collect like terms
212 – 4 = n
208 = n
n = 208
86 = 2 + x
Collect like terms
86 – 2 = x
84 = x
x = 84
ⁿₓD => ²⁰⁸₈₄D = > ²⁰⁸₈₄Po
²¹²₈₆Rn —> ⁴₂He + ²⁰⁸₈₄Po
Thus, option D gives the correct answer to the question.
An insulated bottle contains 150 g of water at 4.0 Celsius. When 90 g of metal at 100 Celsius is placed into the cold water the temperature of both eventually becomes 21 Celsius. assuming no heat is lost to the container or the air, what is the specific heat capacity of the metal? *The specific heat capacity for water is 4200J/Kg°C
Answer:
1506.33J/Kgc
Explanation:
heat loss=heat gain
Qw=Qm
m1c1T1=m2c2T2
0.15×4200×(21-4)=0.09×c2×(100-21)
c2=1506.33J/Kgc
As a 2.0-kg object moves from (4.4 i + 5j) m to ( 11.6 i - 2j) m, the constant resultant force
acting on it is equal to (4i - 9 j) N. If the speed of the object at the initial position is 4.0 m/s,
what is its kinetic energy at its final position?
Answer:
Answer: [tex]107.8\ J[/tex]
Explanation:
Given
Initial position of object is (4.4 i+5 j)
Final position of object is (11.6 i -2 j)
Force acting (4i-9j)
Work done is given by
[tex]\Rightarrow W=F\cdot dx\\\Rightarrow W=(4i-9j)\cdot (11.6i-4.4i-2j-5j)\\\Rightarrow W=(4i-9j)\cdot (7.2i-7j)\\\Rightarrow W=28.8+63\\\Rightarrow W=91.8\ J[/tex]
Initial kinetic energy
[tex]K_i=\dfrac{1}{2}\times 2\times 4^2\\\\K_i=16\ J[/tex]
Change in kinetic energy is equal to work done by object
[tex]\Rightarrow K_f=K_i+W\\\Rightarrow K_f=16+91.8\\\Rightarrow K_f=107.8\ J[/tex]
What is the energy stored in food?
Hey there!
The energy that is stored in food is called CHEMICAL ENERGY
So, when humans/people eat foods their bodies transfigure the energy that is stored which is known as the calories.
Whereas the chains (bonds) in the middle of the atoms in the food humans eat that break up the check mal reactions that has been taken into place and newer compounds will be created. Each food that you eat stores unlikeable amounts of energy
Answer: Chemical energy
Good luck on your assignment and enjoy your day!
~Amphitrite1040:)
I can't seem to get the right angular acceleration and also not sure how to do part b. Help will be much appreciated.
Answer:It’s 5 I believe
Explanation: it says to round to the nearest thousandths, so it’ll be 5.
A rocket moving around the earth at height "H", If the gravitational acceleration "g1" at height
His of gravitational acceleration 'g at earth surface. If Earth radius is "R", find "H"
using R
Answer:
At the earth's surface g = G M / R^2 where G is the gravitational constant
at H g1 = G M / (R + H)^2 using Gauss' theorem for enclosed mass
g1 = G M / (R^2 + 2 R H) ignoring H^2 as it is small compared to R^2
g / g1 = (R^2 + 2 R H) / R^2 = 1 + 2 R H
g = g1 + 2 R H g1
g1 - g = - 2 R H or H = (g1 - g) / 2 R
Which element is the biggest contributor to Climate Change?
Answer:
carbon dioxide (CO2)
Explanation:
the burning or combustion of these fossil fuels creates gases that are released into the atmosphere. Of these gases, carbon dioxide (CO2) is the most common and is the gas most responsible for exacerbating the green- house effect that is changing global climate patterns.
A spherical light bulb dissipates 100W and is of 5cm diameter. Assume the emissivity is 0.8 and the irradiation is negligible. What is the surface temperature of this spherical light bulb
Answer:
[tex]T=728.9K[/tex]
Explanation:
Power [tex]P=100W[/tex]
Diameter [tex]d=5[/tex]
Radius [tex]r=2.5cm=>2.5*10^{-2}m[/tex]
Emissivity [tex]e=0.8[/tex]
Generally the equation for Area of Spherical bulb is mathematically given by
[tex]A=4\pi r^2[/tex]
[tex]A=4\pi (2.5*10^{-2}m)^2[/tex]
[tex]A=7.85*10^{-3}m^2[/tex]
Generally the equation for Emissive Power bulb is mathematically given by
[tex]E=e\mu AT^4[/tex]
Where
[tex]\mu=Boltzmann constants\\\\\mu=5.67*10^{-8}[/tex]
Therefore
[tex]T^4=\frac{E}{e\mu A}[/tex]
[tex]T^4=\frac{100}{0.8*5.67*10^{-8}*7.85*10^{-3}m^2}[/tex]
[tex]T=^4\sqrt{2.80*10^{11}}[/tex]
[tex]T=728.9K[/tex]
1. What is the acceleration of a ball that is vertically tossed up when it reaches its maximum height?
Answer:
Therefore, at maximum altitude the velocity of the ball must be zero. Question: A ball thrown vertically upward reaches a maximum height of 30 meters above the surface of Earth. At its maximum height, the speed of the ball is: Answer: 0 m/s.
Explanation:
Therefore, at maximum altitude the velocity of the ball must be zero. Question: A ball thrown vertically upward reaches a maximum height of 30 meters above the surface of Earth. At its maximum height, the speed of the ball is: Answer: 0 m/s.
A volleyball is served at a speed of 8 / at an angle 35° above the horizontal. What is the speed of the ball when received by the opponent at the same height?
A car (m=1200kg) accelerates at 3m/s/s for d=10m. How much work has the engine done? *
A) 5400J
B) 36000J
C) 352800J
show your work please
This is the answer hope it helps
9) An electrical appliance has a resistance of 25 N. When this electrical ap-
pliance is connected to a 230 V supply line, the current passing through it
will be:
d) 92 A
a) 0.92 A
c) 9.2 A
b) 2.9 A
(C)
Explanation:
From Ohm's law,
V = IR
Solving for I,
I = V/R
= (230 V)/(25 ohms)
= 9.2 A
An oral solution has a dosage of 500 mg in 5 mL. If a 0.7 g dosage is required, how many mL must be given?
Answer:
7 mL
Explanation:
Given that:
mass of an oral solution = 500 mg
solution in mL = 5mL
Thus, the ratio = 5 mL/500 mg
= 0.01 mL/mg
since 1000 mg = 1g
∴
= 0.01 mL/mg × 1000 mg/1g
= 10 mL/g
Now, suppose the amount of 0.7 g dosage is required:
∴
the needed amount of mL will be:
= 10 mL/g × 0.7 g
= 7 mL
According to federal dietary guidelines which if these nutrients is underconsumed ?
Answer:
According to federal dietary guidelines, Magnesium among these nutrients is under-consumed.
The diets of most people in the United States provide less than the recommended amounts of magnesium. Old age (people above 65 to 70 mostly) and younger people are most likely to have low intakes of magnesium.
Low magnesium intake for a long period of time, however, can lead to magnesium deficiency and some severe illness due to these deficiencies.
Explanation:
What is the current running through a parallel circuit containing a 10 V battery and three resistors, each 3 ohms
Answer:
the current through the circuit is 10 A.
Explanation:
Given;
voltage of the battery, V = 10 V
number of the parallel resistors, = 3
resistance of each resistor, r = 3 ohms
The equivalent resistance is calculated as;
[tex]\frac{1}{R_t} = \frac{1}{r_1}+ \frac{1}{r_2} + \frac{1}{r_3} \\\\\frac{1}{R_t} = \frac{1}{3}+ \frac{1}{3} + \frac{1}{3}\\\\\frac{1}{R_t} =\frac{3}{3} \\\\\frac{1}{R_t} = 1\\\\R_t = 1 \ ohms[/tex]
The current through the circuit is calculated as;
V = IRt
I = V/Rt
I = 10/1
I = 10 A
Therefore, the current through the circuit is 10 A.
write the full form of MBBS pliz now
Answer:
The full form of MBBS is Bachelor of Medicine, Bachelor of Surgery
pls mark me brainliest :))
The full form of MBBS in India is 'Bachelor of Medicine, Bachelor of Surgery'. However, MBBS is an abbreviation of Medicinae Baccalaureus Baccalaureus Chirurgiae, which is the term used for this course in Latin.
