Answer:
Answer: Speed is not a vector quantity. It has only magnitude and no direction and hence it is a scalar quantity.
Three identical boxcars are coupled together and are moving at a constant speed of 28.0 m/sm/s on a level, frictionless track. They collide with another identical boxcar that is initially at rest and couple to it, so that the four cars roll on as a unit. Friction is small enough to be neglected.
Required:
a. What is the speed of the four cars?
b. What percentage of the kinetic energy of the boxcars is dissipated in the collision?
c. What happened to this energy?
Answer:
A) v = 21 m /s
B) 25%
C) ) on collision, this energy in the question appears in the form of the following namely; sound energy, heat energy etc
Explanation:
A) Let m be the mass of any of the cars
Thus:
mass of the three cars = 3m
Formula for kinetic energy = ½mv²
Thus, Kinetic energy of 3 identical and coupled cars = ½ x 3m x 28² = 1176 m
KE = 1176 m
Now mass of 4 coupled cars together = 4m
From conservation of linear momentum, we can find the speed of the four cars. Thus;
m1v1 = m2v2
We are told that the 3 coupled moved together with a speed of 28 m/s
Thus;
4m × v = 3m × 28
v = 3m x 28 / 4m
v = 21 m /s
B) from earlier, we saw the formula for kinetic energy. Thus, kinetic energy with of mass of 4 coupled cars together. Thus;
K = ½ x 4m x 21²
K = 882m
Loss of kinetic energy
ΔK = 1176 m - 882 m
ΔK = 294 m
Therefore, percentage of loss is;
%loss = (294 / 1176 ) x 100
%loss = 25 %
C) on collision, this energy in the question appears in the form of the following namely; sound energy, heat energy etc
Can somebody please help
Answer:
Explanation:
part A: C
part B: B
The rotating loop in an AC generator is a square 18 cm on each side. It is rotated at 60.0 Hz in a uniform magnetic field of 0.3T. Calculate the approximate value of the maximum amplitude of the power delivered to the loop for a loop resistance of 12 ohm ?
Answer:
The maximum amplitude power is 1.12 W
Explanation:
Given;
length of each side of the square, L = 18 cm = 0.18 m
angular frequency, f = 60 Hz
magnetic field, B = 0.3 T
resistance of the loop, R = 12 ohm
The area of the loop, A = L² = 0.18 m x 0.18 m = 0.0324 m²
The angular speed, ω = 2πf = 2π x 60 = rad/s = 377.04 rad/s
The maximum value of emf induced;
[tex]E_{max} = NBA \omega\\\\where; \\N \ is \ number \ of \ turns\\\\E_{max} = (1) \times 0.3 \times 0.0324 \times 377.04\\\\E_{max} = 3.665 \ V[/tex]
The maximum amplitude power is calculated as;
[tex]Power = \frac{(E_{max})^2 }{R} \\\\Power = \frac{(3.665)^2}{12} \\\\Power = 1.12 \ W[/tex]
Two identical loudspeakers 2.30 m apart are emitting sound waves into a room where the speed of sound is 340 m/s. Abby is standing 5.00 m in front of one of the speakers, perpendicular to the line joining the speakers, and hears a maximum in the intensity of the sound. Part A What is the lowest possible frequency of sound for which this is possible
Answer:
By the Pythagorean Theorem the distances from the speakers os
5 and 5.5 (rounding) meters - let y be the wavelength in the solution
n y = 5 n is number of wavelengths from speaker
(n + m) y = 5.5 m must be integral for constructive interference
m y = .5 subtracting equations
m = 2 and y = ,25 for the above conditions
(n + 2) y = 5.5 substituting for m
n = 5.5 / .25 - 2 = 20
f = v / y using frequency of sound
f = 340 / .25 = 1360 / sec for lowest frequency
Check: D1 = y n = ,25 * 20 = 5
and D2 = .25 * 22 = 5.5 for the distances traveled
what is the main function of a step-up and step-down transformers
Answer:
Explanation:
The difference between step-up and step-down transformer is given below:-
Step-up transformer
i) It increases the voltage.
ii) It decreases the current strength.
iii) It has a greater number of turns in secondary as compared to the primary.
iv) The wire of primary is thicker than that of the secondary coil.
Step-down transformer
i) It decreases the voltage.
ii) It increases the current strength of the secondary.
iii) It has less number of turns in secondary as compared to the primary.
iv) The wire of the secondary coil is thicker than that of the primary coil.
If a piece of an object is dropped down vertically is the moment of inertia gonna be 0? And why?
Please answer I really need this!!
Answer:
The object is dropped, we know the initial velocity is zero. Once the object has left contact with whatever held or threw it, the object is in free-fall. Under these circumstances, the motion is one-dimensional and has constant acceleration of magnitude g.
No so sure
Explanation:
Hope it helps
what
is the half for physics
one
2
some one help me I need i
Answer:
This Displacement Calculator finds the distance traveled or displacement (s) of an object using its initial velocity (u), acceleration (a), and time (t) traveled. The equation used is s = ut + ½at2; it is manipulated below to show how to solve for each individual vvariation
Friction is a (1)______
that (2)______
motion. It acts in a direction (3)______
to the motion of
the object. There is (4)______
exerted on an object that
moves on a (5)_____
than on a (6)_____
Friction opposes the motion of an object as it moves across a
surface. An object slows down (7)______
on a rough
surface than on a smooth surface.
Answer:
friction is motion heat that collect hot vibration
__5. The study of weather patterns can predict the trajectory and intensity of this
event via satellite imagery.
A. Hurricanes
B. Tornadoes
C. Floods
D. Forest fires
Answer:
its hurricane
Explanation:
beacuse almost all the time hurricanes cause alot of trajectory in the compasses and weather maps
The study of weather patterns can predict the trajectory and intensity of hurricanes. So, option A.
What is meant by weather ?The state of the atmosphere, which includes factors such as temperature, air pressure, wind, humidity, precipitation, and cloud cover, is referred to as the weather.
Here,
Weather condition is the local climate over a specific time period, which might range from one to several weeks. Meteorological conditions are those that are characteristic for a certain place or seasons.
The study of weather and atmospheric patterns across time is known as climatology. This branch of science is devoted to observing, examining, and comprehending global weather patterns, as well as the atmospheric circumstances that lead to them.
The atmosphere's current condition can be determined by combining data from weather stations, satellites, and even data collected by aircraft.
Following that, meteorologists use what they know about atmospheric processes to predict how the atmosphere will change, so altering the weather.
Hence,
The study of weather patterns can predict the trajectory and intensity of hurricanes. So, option A.
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The power in an electrical circuit is given by the equation P= RR, where /is the current flowing through the circuit and Ris the resistance of the circuit. What is the current in a circuit that has a resistance of 100 ohms and a power of 15 watts?
[pleas ee helpppp)
I= 0.39 A
OPTION B is the correct answer.
You throw a stone straight down from the top of a tall tower. It leaves your hand moving at 8.00 m/s, Air resistance can be neglected. Take the positive -direction to be upward, and choose y 0 to be the point where the stone leaves your hand. Find the stone's position 1.50s after it leaves your hand.
Express your answer with the appropriate units.
Find the y-component of the stone's velocity 1.50 s after it leaves your hand. Express your answer with t0he appropriate units.
Answer:
The velocity after 1.5 s is 22.7 m/s downwards.
Explanation:
Initial velocity = - 8 m/s
acceleration, a = - 9.8 m/s2
time, t = 1.5 s
Use first equation of motion
v = u + at
v = - 8 - 9.8 x 1.5
v = - 8 - 14.7
v = - 22.7 m/s
Thus, the velocity after 1.5 s is 22.7 m/s downwards.
A marshmallow in a vacuum becomes
A) larger.
B) smaller.
C) does not change.
puffs up because of aur traping in marshmallow
therefore A is the answer
thank you
A house has well-insulated walls. It contains a volume of 105 m3 of air at 305 K.
Consider heating it at constant pressure. Calculate the energy required to increase the temperature of this diatomic ideal gas by 0.7
Answer: [tex]85.46\ kJ[/tex]
Explanation:
Given
Volume of air [tex]V=105\ m^3[/tex]
Temperature of air [tex]T=305\ K[/tex]
Increase in temperature [tex]\Delta T=0.7^{\circ}C[/tex]
Specific heat for diatomic gas is [tex]C_p=\dfrac{7R}{2}[/tex]
Energy required to increase the temperature is
[tex]\Rightarrow Q=nC_pdT\\\\\Rightarrow Q=n\times \dfrac{7R}{2}\times \Delta T\\\\\Rightarrow Q=\dfrac{7}{2}nR\Delta T\\\\\Rightarrow Q=\dfrac{7}{2}\times \dfrac{PV}{T}\times \Delta T\quad [\text{using PV=nRT}][/tex]
Insert the values
[tex]\Rightarrow Q=\dfrac{7}{2}\times \dfrac{1.01325\times 10^5\times 105}{305}\times 0.7\\ \text{Assuming air pressure to be atmospheric P=}1.01325\times 10^5\ N/m^2\\\\\Rightarrow Q=0.8546\times 10^5\\\Rightarrow Q=85.46\ kJ[/tex]
An alpha particle consists of two protons and two neutrons. How will the emission of an alpha particle affect the following:
a. The atomic number of the atom: _______Atomic Number will go down_______
b. The mass number of the atom: ___Mass number will go down____________
Answer:
a) The atomic number decreases by 2 units
b) the atomic mass decreases by 4 units
Explanation:
An alpha particle is a helium nucleus, which is why it is made up of two positive protons and two negative neutrons, the mass of the particles is almost the same.
a) The atomic number decreases by 2 units
b) the atomic mass decreases by 4 units
A Michelson interferometer operating at a 400 nm wavelength has a 3.70-cm-long glass cell in one arm. To begin, the air is pumped out of the cell and mirror M2 is adjusted to produce a bright spot at the center of the interference pattern. Then a valve is opened and air is slowly admitted into the cell. The index of refraction of air at 1.00 atm pressure is 1.00028.
How many bright-dark-bright fringe shifts are observed as the cell fills with air?
Answer:
[tex]m=42\ fringes[/tex]
Explanation:
From the question we are told that:
Wavelength [tex]\lambda=400nm[/tex]
Length of cell arm [tex]h=3.70cm[/tex]
Refraction of air at at 1.00 atm pressure [tex]n=1.00028.[/tex]
Generally the equation for Number of shifts is mathematically given by
[tex]m=N-N_o[/tex]
Since
[tex]N_0=\frac{2t}{\lambda_0}[/tex]
Therefore
[tex]m=\frac{2t}{\lambda_0/n}-\frac{2t}{\lambda_0}[/tex]
[tex]m=\frac{2t}{\lambda_0} n-1[/tex]
[tex]m=\frac{2(3.7*10^{-2})}{400*10^{-9}}*(1.00028-1)[/tex]
[tex]m=51.8[/tex]
[tex]m=42\ fringes[/tex]
At a rock concert, the sound intensity 1.0m in front of the bank of loudspeakers is 0.10 W/m^2. A fan is 30.0m from the loudspeakers. Her eardrums have a diameter of 8.4mm.How much energy is transferred to each eardrum in one second?
Answer: The amount of energy transferred to each eardrum in one second is [tex]6.2 \times 10^{-9} J[/tex].
Explanation:
Given: Intensity = 0.10 [tex]W/m^{2}[/tex]
Now, at 30.0 m the intensity will be calculated as follows.
[tex]Intensity = \frac{(30.0 m)^{2}}{(1 m)^{2}}\\= 900[/tex]
This means that the intensity is 900 times less assuming that the wave is spherical.
Hence, the new intensity is calculated as follows.
[tex]\frac{0.10 W/m^{2}}{900}\\= 1.11 \times 10^{-4} W/m^{2}[/tex]
The area of ear drum is expressed as follows.
[tex]Area = \pi \times r^{2}\\= 3.14 \times (4.2 mm)^{2}\\= 5.54 \times 10^{-5} m^{2}\\[/tex]
Formula used to calculate energy is as follows.
[tex]P = I \times a[/tex]
where,
P = power or energy
I = intensity
a = area
Substitute the values into above formula as follows.
[tex]P = I \times a\\= 1.11 \times 10^{-4} W/m^{2} \times 5.54 \times 10^{-5} m^{2}\\= 6.2 \times 10^{-9} W[/tex]
Thus, we can conclude that amount of energy transferred to each eardrum in one second is [tex]6.2 \times 10^{-9} J[/tex].
A hockey puck is sliding across the ice with an initial velocity of 25 m/s. If the coefficient of friction between the hockey puck and the ice is 0.08, how much time (in seconds) will it take before the hockey puck slides to a stop
Answer: 31.89seconds
Explanation:
Based on the information given, we are meant to calculate deceleration which will be:
t = V/a
where, a = mg
Therefore, t = V/mg
t = 25/0.08 × 9.8
t = 25/0.784
t = 31.89seconds
Therefore, the time that it will take before the hockey puck slides to a stop is 31.89seconds.
44.7
When Xavier places his hands near a light bulb, he notices that certain areas around the light bulb are warmer than
others. Which best explains this?
The areas to the sides of the light bulb are warmest because of conduction,
O The areas to the sides of the light bulb are warmest because of convection,
The area directly above the light bulb is warmest because of conduction,
The area directly above the light bulb is warmest because of convection.
Save and Exit
Submit
Mark this and retum
Nex
Answer:
The area directly above the light bulb is warmest because of convection.
Explanation:
if all the sides of the bulb are equally close to the light source inside the bulb, all area of the bulb would be equally heated by conduction. however, convection heating mainly heats up the surface above the light source. in convection heating, the air above the surface of the light source get heated by the light source and expands, casuing it to be less dense and rise to the top of the bulb. colder denser air at the top of the bulb sink to the light source adn gain heat and expands, becoming less dense. this process repeats and the surface above the light source becomes the warmest due to convection heating
How much power does it take to lift 70.0 N to 5.0 m high in 5.00 s?
Answer:
Power = 70 W
Explanation:
Given that,
Force, F = 70 N
Height, h = 5 m
Time, t = 5 s
We need to find the power of the object. We know that,
Power = work done/time
Put all the values,
[tex]P=\dfrac{Fd}{t}\\\\P=\dfrac{70\times 5}{5}\\\\P=70\ W[/tex]
So, the required power is 70 W.
The colors that make up white light are called what?
Answer:
The ROYGBIV
Explanation:
R - red
O - orange
Y - yellow
G - green
B - blue
I - indigo
V - violet
A 3.7-kg object is acted on by two forces. One of the forces is 11 N acting toward the
east. What is the other force if the acceleration of the object is 1.0 m/s2 toward the east?
Answer:
7.3 newtons to the west
Explanation:
3.7kg × 11a - 3.7kg × ? = 3.7n
for the long life cells we have to connect them in ____ combination
Answer:
Parallel combination.
for the long life cells we have to connect them in parallel combination
hope it is helpful to you
If you exert a force of 5 N into a nutcracker, and it outputs a force of 20 N, what is the mechanical advantage of the nutcracker. Show formula PLSSS HELPPPP!!! i'll make you brainliest
Answer: 4
Explanation:
MA = output force / input force
MA = 20 / 5
MA = 4
Hope this helps. Please mark brainliest.
Suppose 4 J of work are needed to stretch a spring 14 cm from its natural position. How much work is needed to stretch it 20 cm from its natural position
Answer:
8.16 J
Explanation:
Applying,
W = ke²/2................. Equation 1
Where W = work done in stretching the spring, k = spring constant, e = extension
make k the subject of the equation
k = 2W/e²................ Equation 2
From the question,
Given: W = 4 J, e = 14 cm = 0.14 m
Substitute these values into equation 2
k = 2(4)/0.14²
k = 8/0.0196
k = 408.16 N/m
If stretchd 20 cm from its natural length,
Therefore,
e = 20 cm = 0.2 m
W = 408.16(0.2²)/2
W = 8.16 J
The bus travelled at velocity 15 ms-l for 5 minutes before it came to a stop. By using suitable linear equation, calculate the distance the bus has travelled.
Answer:
ans: 2250 meters
Explanation:
initial velocity (U)= 15 m/s
final velocity (V) = 0m/s , since need to come in rest
total time taken (T) = 5 min= 300 seconds
total distance covered (S)= UT + 1/2 aT^2 ,
a= acceleration
S= 15 × 300 + 0.5 ×(0 - 15) × 300
since a = (V - U)/ T
S = 4500 - 2250
S= 2250 m
You throw a football straight up. Air resistance can be neglected. When the football is 4.00 mm above where it left your hand, it is moving upward at 0.500 m/sm/s. What was the speed of the football when it left your hand
Answer:
u=8.868 m/s
Explanation:
The displacement of the ball is 4 meters
The final speed of the ball is 0.5 m/s
The initial speed of the ball is to be calculated. Using the equation of the rectilinear motion,
[tex]v^{2} =u^{2} +2as[/tex]
Plugging the values in the above expression,
[tex]\\0.5^{2} =u^{2} +2*(-9.8)*4\\\\u^{2} =78.4+0.25\\\\u^{2} =78.65\\\\u=8.868 m/s[/tex]
The triceps muscle in the back of the upper arm extends the forearm. This muscle in a professional boxer exerts a force of 2.00\times 10^32.00×10 ^3 N with an effective perpendicular lever arm of 3.00 cm, producing an angular acceleration of the forearm of 120 rad/s^2 .
What is the moment of inertia of the boxer's forearm?
Answer:
Explanation:
From the given information:
The torque produced due to the force can be expressed as:
[tex]\tau = F \times r[/tex]
where;
[tex]\tau[/tex] = torque
F = force exerted
r = lever's arm radius
[tex]\tau[/tex] = [tex]2.00 \times 10^3 \times 0.03 m[/tex]
[tex]\tau[/tex] = 60 N.m
However, equating the torque with the moment of inertia & angular acceleration, we use the equation:
[tex]\tau[/tex] = I∝
60 Nm = I × 120 rad/s²
I = 60 Nm/120 rad/s²
I = 0.5 kg.m²
how is the process that generates energy in the suns core different from an explosion caused by a chemical reaction
Answer:
[tex]$E = m{c^2}$[/tex]
Explanation:
• The explosion caused by chemical reaction involves conversion of chemical energy into heat and sound, but the total mass of atoms participating in the reaction remains constant.
• In the nuclear fusion reaction, the one happening in the core of the sun, mass is directly converted into energy by the equation [tex]E=mc^{2}[/tex]
Hence, mass remains constant, it just converts in to velocity.
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Which of the following statements regarding the warming of the troposphere (i.e., the lower atmosphere) are TRUE (choose all that apply):
a. Conduction only warms the shallow layer of air within a few centimeters of the ground
b. The troposphere is heated mainly from above
c. Atmospheric gases do not readily absorb solar radiation
d. The troposphere is heated mainly by direct molecule-to-molecule contact
e. Condensation of water vapor plays a role in heating the lower atmosphere
f. Oxygen and nitrogen readily absorb and emit terrestrial radiation
g. Convection distributes heat vertically
Answer: • Conduction only warms the shallow layer of air within a few centimeters of the ground
• Atmospheric gases do not readily absorb solar radiation
• Condensation of water vapor plays a role in heating the lower atmosphere.
• Convection distributes heat vertically
Explanation:
The statements regarding the warming of the troposphere that are true include:
• Conduction only warms the shallow layer of air within a few centimeters of the ground
• Atmospheric gases do not readily absorb solar radiation
• Condensation of water vapor plays a role in heating the lower atmosphere.
• Convection distributes heat vertically.
Therefore, the correct options are A, C, E and G.
• Conduction only warms the shallow layer of air within a few centimeters of the ground
• Atmospheric gases do not readily absorb solar radiation
• Condensation of water vapor plays a role in heating the lower atmosphere.
• Convection distributes heat vertically
What is troposphere?The lowest layer of the atmosphere of the earth is the troposphere. Most of the mass (about 75-80%) of the atmosphere is in the troposphere.
Most types of clouds are found in the troposphere, and almost all weather occurs within this layer.
The statements regarding the warming of the troposphere that are true include:
• Conduction only warms the shallow layer of air within a few centimeters of the ground
• Atmospheric gases do not readily absorb solar radiation
• Condensation of water vapor plays a role in heating the lower atmosphere.
• Convection distributes heat vertically.
Thus a,c,e,g are the correct statements regarding the warming of the troposphere
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A ball player catches a ball 3.55 s s after throwing it vertically upward. with what speed did he throw it
Answer:
i believe he threw the ball up at about 18 mph
Explanation: