1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Semmy [17]
3 years ago
13

Your Lead Teaching Assistant is initially seated on the top of a hemispherical ice mound of radius R = 30 m. Approximate the ice

as being frictionless. He begins to slide down the ice with a negligible initial speed. At what height does the TA lose contact with the ice?
Physics
2 answers:
saw5 [17]3 years ago
7 0

Answer:

<em>Height = 5.65 km</em>

Explanation:

3\pi r^2 is the circumference or we can say measures the boundary of hemisphere of friction-less ice that he is sitting on.

So, the height will be = 2 x 3.14 x (30)^2 = 5654.7 m = 5.65 km

Montano1993 [528]3 years ago
3 0

Answer:

Height at which lead assistant will lose the contact with ice = h = 20 m

Explanation:

The height at which the lead assistant will lose the contact with the ice can be found using the following formula:

                          h = 2R/3   ……… (i)

Where R is the radius of the hemisphere. So,

                          h = 2(30)/3

                          h = 2(10)

                          h = 20 m

Hence, the lead assistant will lose the contact with the ice at the height of 20 m.  

You might be interested in
A transformer has a secondary voltage of 140 volts and a secondary current of 3.5 amps. if the primary current is 10 amps, what
Lynna [10]

For an ideal transformer power loss is assumed to be zero

i.e. the power in primary coil due to input voltage must be equal to power in secondary coil due to output voltage

this can be written in form of equation

V_1 i_1 = V_2 i_2

here we know that

V_2 = 140 volts

i_2 = 3.5 A

i_1 = 10 A{/tex]now we will use above equation[tex]140*3.5 = 10 * V_1

V_1 = 49 volts

So primary coil voltage is 49 Volts

7 0
3 years ago
A research vessel is mapping the bottom of the ocean using sonar. It emits a short sound pulse called "ping" downward. The frequ
Elena L [17]

Answer:

The ocean is 6485.6m deep when measured from the vessel

Explanation:

v=1474m/s

t=8.88s

let d represent distance from the vessel to the ocean bottom.

an echo travels a distance equivalent to 2d, that is to and fro after it reflects from the obstacle.

velocity=\frac{distance}{time}\\ v=\frac{2d}{t} \\vt=2d\\d=\frac{vt}{2}

d=\frac{1474*8.8}{2}

d= 6485.6m

7 0
3 years ago
A brick of mass 2.0kg is at rest. It falls to the ground through a
Lisa [10]

Answer:

I may not have the answer so i'll just give up some hints.

Multiply the time by the acceleration due to gravity to find the velocity when the object hits the ground. If it takes 9.9 seconds for the object to hit the ground, its velocity is (1.01 s)*(9.8 m/s^2), or 9.9 m/s. Choose how long the object is falling. In this example, we will use the time of 8 seconds. Calculate the final free fall speed (just before hitting the ground) with the formula v = v₀ + gt = 0 + 9.80665 * 8 = 78.45 m/s . Find the free fall distance using the equation s = (1/2)gt² = 0.5 * 9.80665 * 8² = 313.8 m .h = 0.5 * 9.8 * (1.5)^2 = 11m. b. V = gt = 9.8 * 1.5 = 14.7m/s. A feather and brick dropped together. Air resistance causes the feather to fall more slowly. If a feather and a brick were dropped together in a vacuum—that is, an area from which all air has been removed—they would fall at the same rate, and hit the ground at the same time.When an object's point is taller the thing that is going down it will go faster than when the point is lower. EXAMPLE: The object is the tennis ball if you drop it down the higher hill it will be faster than if you drop it down a shorter hill. In other words, if two objects are the same size but one is heavier, the heavier one has greater density than the lighter object. Therefore, when both objects are dropped from the same height and at the same time, the heavier object should hit the ground before the lighter one.

I hope my little bit (big you may say) hint help you with your question.

5 0
3 years ago
What are the characteristics of the radiation emitted by a blackbody? According to Wien's Law, how many times hotter is an objec
jasenka [17]

Answer:

a) What are the characteristics of the radiation emitted by a blackbody?

The total emitted energy per unit of time and per unit of area depends in its temperature (Stefan-Boltzmann law).

The peak of emission for the spectrum will be displaced to shorter wavelengths as the temperature increase (Wien’s displacement law).

The spectral density energy is related with the temperature and the wavelength (Planck’s law).

b) According to Wien's Law, how many times hotter is an object whose blackbody emission spectrum peaks in the blue, at a wave length of 450 nm, than a object whose spectrum peaks in the red, at 700 nm?

The object with the blackbody emission spectrum peak in the blue is 1.55 times hotter than the object with the blackbody emission spectrum peak in the red.

Explanation:

A blackbody is an ideal body that absorbs all the thermal radiation that hits its surface, thus becoming an excellent emitter, as these bodies express themselves without light radiation, and therefore they look black.

The radiation of a blackbody depends only on its temperature, thus being independent of its shape, material and internal constitution.

If it is study the behavior of the total energy emitted from a blackbody at different temperatures, it can be seen how as the temperature increases the energy will also increase, this energy emitted by the blackbody is known as spectral radiance and the result of the behavior described previously is Stefan's law:

E = \sigma T^{4}  (1)

Where \sigma is the Stefan-Boltzmann constant and T is the temperature.

The Wien’s displacement law establish how the peak of emission of the spectrum will be displace to shorter wavelengths as the temperature increase (inversely proportional):

\lambda max = \frac{2.898x10^{-3} m. K}{T}   (2)

Planck’s law relate the temperature with the spectral energy density (shape) of the spectrum:

E_{\lambda} = {{8 \pi h c}\over{{\lambda}^5}{(e^{({hc}/{\lambda \kappa T})}-1)}}}  (3)

b) According to Wien's Law, how many times hotter is an object whose blackbody emission spectrum peaks in the blue, at a wavelength of 450 nm, than a object whose spectrum peaks in the red, at 700 nm?

It is need it to known the temperature of both objects before doing the comparison. That can be done by means of the Wien’s displacement law.

Equation (2) can be rewrite in terms of T:

T = \frac{2.898x10^{-3} m. K}{\lambda max}   (4)

Case for the object with the blackbody emission spectrum peak in the blue:

Before replacing all the values in equation (4), \lambda max (450 nm) will be express in meters:

450 nm . \frac{1m}{1x10^{9} nm}  ⇒ 4.5x10^{-7}m

T = \frac{2.898x10^{-3} m. K}{4.5x10^{-7}m}

T = 6440 K

Case for the object with the blackbody emission spectrum peak in the red:

Following the same approach above:

700 nm . \frac{1m}{1x10^{9} nm}  ⇒ 7x10^{-7}m

T = \frac{2.898x10^{-3} m. K}{7x10^{-7}m}

T = 4140 K

Comparison:

\frac{6440 K}{4140 K} = 1.55

The object with the blackbody emission spectrum peak in the blue is 1.55 times hotter than the object with the blackbody emission spectrum peak in the red.

4 0
3 years ago
Lord Beckett and members of the EIT Co. spot the Black Pearl in the distance making its way towards land. As a
KATRIN_1 [288]

Answer:

Explanation:

The cannonball goes a horizontal  distance of 275 m . It travels a vertical distance of 100 m

Time taken to cover vertical distance =  t ,

Initial velocity u = 0

distance s = 100 m

acceleration a = 9.8 m /s²

s = ut + 1/2 g t²

100 = .5 x 9.8 x t²

t = 4.51 s

During this time it travels horizontally also uniformly so

horizontal velocity Vx = horizontal displacement / time

= 275 / 4.51 = 60.97 m /s

Vertical velocity Vy

Vy = u + gt

= 0 + 9.8 x 4.51

= 44.2 m /s

Resultant velocity

V = √ ( 44.2² + 60.97² )

= √ ( 1953.64 + 3717.34 )

= 75.3 m /s

Angle with horizontal Ф

TanФ = Vy / Vx

= 44.2 / 60.97

= .725

Ф = 36⁰ .

6 0
2 years ago
Other questions:
  • Find the average velocity of the object from point B to C.
    13·1 answer
  • What is the speed of light?
    9·2 answers
  • The Pinnacles and Neenach volcanics are 23.5 million-year-old andesite to rhyolite outcrops, on either side of the San Andreas F
    14·1 answer
  • The number of waves produced in a given time is the ____ of the wave
    9·1 answer
  • A capacitor is discharged through a 30.0 Ω resistor. The discharge current decreases to 26.0% of its initial value in 3.00 ms .
    8·1 answer
  • (quick help please??)A mechanic uses a mechanical lift to raise a car. The car weighs 10,200 N. The work required to do this was
    14·1 answer
  • A truck travels at a speed of 40 mph. How long does it take to travel<br> 240 miles?
    5·1 answer
  • Suppose a particle is accelerated through space (no gravity) by a 10 N force. Suddenly the particle encounters a second force of
    6·1 answer
  • A Net Force Of 60 N Accelerates A 4-kg Mass Over A Distance Of 10 M.
    9·1 answer
  • How many minutes will it take a car to go from a stop to 33 km/hr if it accelerates at 10 km/hr²
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!