Question:
A particle is trapped in a 20 nm wide infinite potential well. What is the wavelength of the particle corresponding to n = 7 in nm?
Answer:
[tex]\lambda_n = 5.71\ nm[/tex]
Explanation:
Given
[tex]L = 20nm[/tex] --- the width
[tex]n = 7[/tex]
Required
Determine the wavelength ([tex]\lambda[/tex])
This is calculated as:
[tex]\lambda_n = \frac{2L}{n}[/tex]
Substitute values for L and n
[tex]\lambda_n = \frac{2*20nm}{7}[/tex]
[tex]\lambda_n = \frac{40nm}{7}[/tex]
[tex]\lambda_n = \frac{40}{7}nm[/tex]
[tex]\lambda_n = 5.71428571\ nm[/tex]
[tex]\lambda_n = 5.71\ nm[/tex] --- approximated to 3 significant figures
In the final stages of production, a pharmaceutical is sterilized by heating it from 25 to 75C as it moves at 0.2 m/s through a straight thin-walled stainless steel tube of 12.7-mm diameter. A uniform heat flux is maintained by an electric resistance heater wrapped around the outer surface of the tube. If the tube is 10 m long, what is the required heat flux
Answer:
The answer is "[tex]12682.267\ \ \frac{W}{m^2}[/tex]"
Explanation:
Calculating the mass flow rate of fluid:
[tex]m= \rho AV[/tex]
[tex]= \rho \frac{\pi}{4} D^2\ V\\\\= 100 \times \frac{\pi}{4} \times (0.0127)^2\times 0.2\\\\=0.0253 \ \frac{kg}{s}\\\\[/tex]
Calculating the amount of heat transfer.
[tex]q =m\timesC_p(T_{m,0}-T_{m,i})[/tex]
[tex]=0.0253 \times 4000 (75-25)\\\\=0.0253 \times 4000(50)\\\\=0.0253 \times 200,000 \\\\= 5060 \ W[/tex]
Calculating the required value for heat flux:
[tex]q"=\frac{q}{A_s}[/tex]
[tex]=\frac{q}{\pi DL}\\\\= \frac{5060}{\pi \times 0.0127 \times 10}\\\\= 12682.267 \frac{W}{m^2}\\[/tex]
suppose you want to determine the surface area of this sugar cube. it has edges that are each 2 cm long. if you cut the cube in half what is the surface area of each half? what is the total surface area of both halves
Answer:
Half: 6 cm^2 Whole: 12 cm^2
Explanation:
First, we know that the edges of the cube are 2 cm long. So there are 6 faces on a cube. We do 2x6=12 cm^2 as our total surface area. Then it asks for each half. So you would divide it by 2 and get 6 cm^2 as your half.
A 0.100-kg ball is thrown with a speed of 20.0 m/s at an angle of 30.0° with the horizontal. Find
the momentum of the ball (a) at its maximum height, and (b) just before it strikes the ground.
Answer:
25.0
Explanation:
A jet aircraft with a mass of 4,250 kg has an engine that exerts a force (thrust) equal to 60,100 N.
(a) What is the jet's acceleration when it takes off? (Give the magnitude.)
m/s2
(b)What is the jet's speed after it accelerates for 9 s? (Assume it starts from rest.)
m/s
(c) How far does the jet travel during the 9 s?
m
Answer:
A. 14.14 m/s²
B. 127.26 m/s
C. 572.67 m
Explanation:
From the question given above, the following data were obtained:
Mass (m) of jet = 4250 kg
Force (F) = 60100 N
A. Determination of the acceleration of the jet.
Mass (m) of jet = 4250 kg
Force (F) = 60100 N
Acceleration (a) =?
F = ma
60100 = 4250 × a
Divide both side by 4250
a = 60100 / 4250
a = 14.14 m/s²
B. Determination of the speed of the jet after 9 s.
Initial velocity (u) = 0 m/s
Acceleration (a) = 14.14 m/s²
Time (t) = 9 s
Final velocity (v) =?
v = u + at
v = 0 + (14.14 × 9)
v = 0 + 127.26
v = 127.26 m/s
C. Determination of the distance travelled during the time.
Initial velocity (u) = 0 m/s
Acceleration (a) = 14.14 m/s²
Time (t) = 9 s
Distance travelled (s) =?
s = ut + ½at²
s = (0 × 9) + (½ × 14.14 × 9²)
s = 0 + (7.07 × 81)
s = 0 + 572.67
s = 572.67 m.
Two different liquids are poured into a jar until it is half full. The jar is then sealed shut and shaken. The liquids undergo a chemical reaction that releases thermal energy and also
emits a new gas into the far. The new gas increases the pressure inside the jar. After the far is sealed, it is an example of an)
Answer:
A closed system.
Explanation:
The three major types of system are: open, closed and isolated. Open system interacts with its surroundings with respect to its particles and energy. A closed system interacts with its surroundings with respect to energy but not its particles. While an isolated system does not interact with its surroundings in any way.
Therefore, after the jar is sealed, it is an example of a closed system. This is because the emitted gas could not escape into the surroundings, but thermal energy was emitted into its surroundings after the chemical reaction has taken place.
The diagram shows a proposed design for a ship that could be used for long-distance space travel. Explain why the ship must rotate so that passengers feel effects similar to gravity.
Answer:
I don't know this for sure, but I think its because they need to be able to sit in their seats without flying in the air.
Explanation:
Because of the centrifugal force he ship must rotate so that passengers feel effects similar to gravity.
What is Centrifugal force ?''Centrifugal force is force acting on a body performing circular motion, which is along radius of the circle and directed outwards from the center of circle". Since Centrifugal force acts at right angle to the tangential velocity of the body, there is no displacement in the direction of the force, hence no work done. It has newton(N) as Si unit.
centripetal force is given by,
F= mv²÷r
Where m is mass of the body v is velocity of the body r is radius of circle at which body is moving.
When space ship rotate to the certain angular velocity, centrifugal force will act on each object in the space ship. that force will force the object radially outwards as result all will stuck on the floor and all will experience the feel of gravity.
To know more about gravity :
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CAN SOMEONE PLEASE HELPPPPPP
Answer:
0.54
Explanation:
2.7÷5 = 0.54
Hope this helps!
6.8. A marble with a mass m of 3.00 g is released from rest in a bottle of syrup. Its terminal speed vt is 1.79 cm/s. (a) Presuming the resistive force R = −bv, what is the value of b (N s/m)? (b) What is the strength of the resistive force (N) when the marble reaches terminal speed? (c) How long in milliseconds does it take for it to reach a speed of 0.600vt?
Answer:
a. 1.642 Ns/m b. 0.0294 N c. 5 × 10⁵ ms
Explanation:
a. Presuming the resistive force R = −bv, what is the value of b (N s/m)?
Using the equation of motion on the object,
W + R = ma where W = weight of the mass = mg where m =mass of marble = 3.00 g = 0.003 kg and g = acceleration due to gravity = 9.8 m/s² , R = resistive force = -bv where v = velocity and a = acceleration of marble.
So,
mg - bv = ma
At terminal speed, a = 0,
So, mg - bvt =m(0)
mg - bvt = 0
mg = bvt
b = mg/vt since terminal speed vt = 1.79 cm/s = 0.0179 m/s
So, b = 0.003 kg × 9.8 m/s²/0.0179 m/s
b = 0.0294 kgm/s² ÷ 0.0179 m/s
b = 1.642 Ns/m
b. What is the strength of the resistive force (N) when the marble reaches terminal speed?
Since the resistive force R = -bv, at terminal speed, vt
R = -bvt
R = -1.642 Ns/m × 0.0179 m/s
R = -0.0294 N
So, its strength is 0.0294 N
(c) How long in milliseconds does it take for it to reach a speed of 0.600vt?
Using mg - bv = ma where a = dv/dt,
mg - bv = mdv/dt
g - bv/m = dv/dt
separating the variables, we have
dv/(g - bv/m) = dt
Integrating, we have
∫dv/(g - bv/m) = ∫dt
(-b/m)/(-b/m) × ∫dv/ (g - bv/m) = ∫dt
1/(-b/m) ∫(-b/m)dv/(g - bv/m) = ∫dt
1/(-b/m) ㏑(g - bv/m) = t + C
㏑(g - bv/m) = -m/bt - mC/b
㏑(g - bv/m) = -m/bt + C' (C' = -mC/b)
taking antilogarithm of both sides, we have
g - bv/m = exp(-m/bt + C')
g - bv/m = exp(-m/bt)expC'
g - bv/m = Aexp(-m/bt) (A = expC')
bv/m = g - Aexp(-m/bt)
v = mg/b - (Am/b)exp(-m/bt)
when t = 0, v = 0 (since the marble starts from rest)
0 = mg/b - (Am/b)exp(-m/b(0))
0 = mg/b - (Am/b)exp(0))
-mgb = -Am/b
A = g
v = mg/b - (mg/b)exp(-m/bt)
when v = 0.600vt = 0.600 × 0.0179 m/s = 0.01074 m/s
mg/b = 0.003 kg × 9.8 m/s²/1.642 Ns/m = 0.0179 m/s and m/b = 0.003 kg/1.642 Ns/m = 0.00183/s
So,v = mg/b - (mg/b)exp(-m/bt)
0.01074 m/s = 0.0179 m/s - (0.0179 m/s)exp[(-0.00183/s)t]
0.01074 m/s - 0.0179 m/s = - (0.0179 m/s)exp[(-0.00183/s)t]
-0.00716 m/s = - (0.0179 m/s)exp[(-0.00183/s)t]
exp[(-0.00183/s)t] = -0.00716 m/s/-0.0179 m/s
exp[(-0.00183/s)t] = 0.4
taking natural logarithm of both sides, we have
(-0.00183/s)t = ㏑(0.4)
(-0.00183/s)t = -0.9163
t = -0.9163/-0.00183
t = 500 s
t = 500 × 1000 ms
t = 5 × 100000
t = 5 × 10⁵ ms
What is an indicator that the universe is exapanding?
Answer:
*Doppler effect by the displacement or towards the red
*The microwave temperature of the universe
Explanation:
The expansion of the universe can be visualized in various facts
* the stars and galaxies are moving away from us, this is observed in the Doppler effect by the displacement or towards the red of the hydrogen lines.
* The microwave temperature of the universe that comes from everywhere, this temperature is the rest of the temperature of an initial great explosion (big ban), for which the expanding universe must cool down.
A 30.8 kg box rests on an incline of 13 degrees. What is the normal force, in Newtons, exerted by the incline?
so 30.8/13= is 2.369
so round your ans to I dp which is
2.4d/kg
A 55 kg skater spins with a speed of 7.2 m/s with her arms outstretched making a
radius of 0.6 m. Calculate the angular momentum of the skater. *
33 kg m^2/s
0 237.6 kg m^2/s
396 kg m^2/s
660 kg m^2/s
e xddd snoAnswer:n
E
xplanation:s no
What is the potential energy at point e when the total mechanical energy is 4900 for the 100 kg moving at 2 m/ s
Answer:
B. 4700 J
Explanation:
Given the following data;
Mechanical energy = 4900J
Mass = 100kg
Velocity = 2m/s
To find the potential energy;
Mechanical energy = kinetic energy + potential energy
First of all, we would determine the kinetic energy of the object;
K.E = ½mv²
K.E = ½*100*2²
K.E = 50*4
K.E = 200 J
Substituting into the equation, we have;
4900 = 200 + P.E
P.E = 4900 - 200
P.E = 4700 Joules
What are some of the physical properties of minerals
Answer:
hardness, luster, color, streak, specific gravity, cleavage, fracture, and tenacity.
Explanation:
doesn't really need one.
Janice jumps directly up into the air. Which direction is she accelerating as she moves upward?
A Up
B.
Down
C.
Not accelerating
Answer:
b down
Explanation:
because as she is jumping she is bending her nees so the acceleration is down words
Answer:
b down
Explanation:
How can an electromagnet be made stronger?
A.Add more coils of wire.
B.Add an iron core.
C.All the above.
D.Increase the voltage.
All four choices are correct responses. (A), (B), (C), (D)
What is Gravitational force?
Answer:
the force of attraction between all masses in the universe; especially the attraction of the earth's mass for bodies near its surface
Explanation:
Answer:
Gravitational force is the force of attraction in which body having certain mass in the universe attracts every other body which is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
A toy car of mass 1.2 kg is driving vertical circles inside a hollow cylinder of radius 2.0m. It is moving at a constant speed of 6 m/s. a) Calculate the magnitude of the normal force acting on the car when it is on the top of the circle and when it is on the bottom of the circle, respectively. b) What is the minimum speed the car needs to go around the circle without falling off
Answer:
a)[tex]|N|=9.83\: N[/tex] at the top
[tex]|N|=33.37\: N[/tex] at the botton
b) The minimum velocity will be [tex]v=4.43\: m/s[/tex].
Step-by-step explanation:
a) Using the second Newton's law, at the top of the circle we have.
[tex]\Sigma F=ma_{c}[/tex]
The forces at the top are the weight and the normal force.
[tex]W-N=m\frac{v^{2}}{R}[/tex]
[tex]mg-N=m\frac{v^{2}}{R}[/tex]
[tex]N=mg-(m\frac{v^{2}}{R})[/tex]
[tex]N=1.2*9.81-(1.2\frac{6^{2}}{2})[/tex]
[tex]N=-9.83\: N[/tex]
[tex]|N|=9.83\: N[/tex]
At the botton of the circle we have:
[tex]N-W=m\frac{v^{2}}{R}[/tex]
[tex]N-mg=m\frac{v^{2}}{R}[/tex]
[tex]N=1.2*9.81+(1.2\frac{6^{2}}{2})[/tex]
[tex]|N|=33.37\: N[/tex]
b) If we do the normal force equal to zero we can find the minimum velocity, which means:
[tex]W-0=m\frac{v^{2}}{R}[/tex]
[tex]mg=m\frac{v^{2}}{R}[/tex]
[tex]v=\sqrt{Rg}[/tex]
[tex]v=\sqrt{2*9.81}[/tex]
Therefore, the minimum velocity will be [tex]v=4.43\: m/s[/tex].
I hope it helps you!
1. The more velocity an object has the harder it is to slow
it down, speed it up, or turn it.
Answer:
The more velocity an object has the harder it is to slow it down
Explanation:
slow it down
How do motion and Newton's laws apply to your everyday life? (all of the laws)
Answer:
This may help
Examples of Newton's third law of motion are ubiquitous in everyday life. For example, when you jump, your legs apply a force to the ground, and the ground applies and equal and opposite reaction force that propels you into the air. Engineers apply Newton's third law when designing rockets and other projectile devices.
Explanation:
She walks 50 yards north 20 yards east 50 yards south what is total displacement
Answer:
|---20----|
| |
| 50 |50
|---D--->|
Start End
Total displacement(D) 20 yards (East).
Explanation:
why do bees sting i think they do because when the get disturbed they use thier stinger to sting people
Find the momentum of an object traveling at 15 m/s if it has a mass of 2. I kg?
Answer:
momentum=31.5
Explanation:
given,
mass(m)=2.1kg
velocity(v)=15m/s
momentum(p)=?
now,
p=mv
p=15×2.1
p=31.5 kgm/s
Assume the ground is uniformly level. If the horizontal component a projectile's velocity is doubled, but the vertical component is unchanged, what is the effect on the time of flight
Answer:
Explanation:
Time of flight = 2 x u sinα / g where u sinα is vertical component of projectile's velocity u .
So Time of flight = 2 x vertical component / g
vertical component = constant
g is also constant so
Time of flight will also be constant .
It will remain unchanged .
A train takes 2.5 hours to travel 120 kilometers. What is the train's average speed?
A: 0.02 hr/km
B: 48 km/hr
C: 48 hr/km
D: 0.02 km/hr
PLS HELPPP
Answer:
48
Explanation:
The formula is d, time t, and speed or rate of travel r is:
d = rt.
We know that d = 120 km and t = 2 hours and 30 minutes = 2.5 hrs.
So you now plug in for d and t to find r, we get:
120 km = r(2.5 hrs)
divide both sides by 2.5 and we get
120 km/2.5 hrs = [r(2.5 hrs)]/2.5 hrs
120 km/2.5 hrs = r(2.5 hrs/2.5 hrs)
48 km/hr = r(1)
r = 48 km/hr
Speed = (distance covered) / (time to cover the distance)
Speed = (120 km) / (2.5 hr)
Speed = (120/2.5) (km/hr)
Speed = 48 km/hr (B)
3. Two balls are released from the same height. One is released from rest and the other is thrown straight down. Which
will have the larger acceleration as they fall neglecting air resistance?
a. The dropped ball
b. The thrown ball
c.They will have the same accelerations
Answer:
B. The thrown ball
Explanation:
because you are giving the ball a higher force causing the acceleration to be higher
What is the length of the x-component of the vector shown below?
c. 6.6
What is x component?The x-component of a vector can be either sinθ or cosθ, depending on which angle you are given.
Cosθ always goes with the side of a right triangle that is adjacent to (touches) the given angle.
The projection of a vector quantity on the x axis of a coordinate system.
If you shine a light straight down onto that vector, then the length of its shadow on the x-axis is
x-component = 8· cosine(34°)
x-component = 8 · (0.829)
x-component = 6.6
Therefore,
6.6 is the length of the x-component of the vector.
Learn more about x- component here:
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an oscillator with a mass of 310 g and a period of 0.180 s has amplited that decreases by 20 % during each complete oscillation what is the damping constant
Answer:
1.241/s
Explanation:
From this question, we have the following information:
Mass of oscillator = 310
The time Period, t = 0.180
Decrease = 20 %
Amplitude of oscillation has the formula
A = Aoe^yt
1-20% = 80%
= 0.80
Y x 0.18 = -ln(0.8)
= 0.18Y = 0.2234
Y = 0.2233/0.18
Y = 1.241/s
The damping constant y is Therefore equal to 1.241s
**WILL MARK BRAINLIEST IF CORRECT**
The wavelength of light released from a hydrogen atom depends on the
Select one:
a.
excited state and ground state of an electron.
b.
proton to neutron ratio of the nucleus.
c.
the number of electrons the hydrogen atom has.
d.
type of filter being used to view the light.
Answer:
a
Explanation:
What is the kinetic energy of a 2122 kg car parked in a parking lot?
Answer:
There is no kinetic energy.
Explanation:
Since K=1/2mv^2 where m=2122kg and v=0, clearly the car has no kinetic energy as multiplying by 0 results in 0. If the car were moving, there would be kinetic energy.
Need help with this pleases