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
NNADVOKAT [17]
3 years ago
13

An elevator suspended by a vertical cable is moving downward at a constant speed. The tension in the cable must be A) greater th

an the weight of the elevator. B) less than the weight of the elevator. C) equal to the weight of the elevator.
Physics
1 answer:
True [87]3 years ago
8 0

Answer:

(C) because the elevator is not accelerating

Note  F = M a = M g (the resultant force on the elevator is due to gravity)

or  Fup = Fc   the force exerted on the elevator by the cable

and Fdown = Fe    the force exerted on the elevator by gravity

F = M a = Fup - Fdown = zero    resultant force on elevator

You might be interested in
You are working on a laboratory device that includes a small sphere with a large electric charge Q. Because of this charged sphe
madam [21]

Answer:

the only effect it has is to create more induced charge at the closest points, but the net face remains zero, so it has no effect on the flow.

Explanation:

We can answer this exercise using Gauss's law

      Ф = ∫ e . dA = q_{int} / ε₀

field flow is directly proportionate to the charge found inside it, therefore if we place a Gaussian surface outside the plastic spherical shell.  the flow must be zero since the charge of the sphere is equal  induced in the shell, for which the net charge is zero. we see with this analysis that this shell meets the requirement to block the elective field

From the same Gaussian law it follows that if the sphere is not in the center, the only effect it has is to create more induced charge at the closest points, but the net face remains zero, so it has no effect on the flow , so no matter where the sphere is, the total induced charge is always equal to the charge on the sphere.

5 0
3 years ago
To teach you how to find the parameters characterizing an object in a circular orbit around a much heavier body like the earth.
Karolina [17]

Answer:

a)  T² = (\frac{4\pi ^2}{GM})  r³

b) veloicity the dependency is the inverse of the root of the distance

kinetic energy  depends on the inverse of the distance

potential energy dependency is the inverse of distance

angular momentum depends directly on the root of the distance

Explanation:

1) for this exercise we will use Newton's second law

            F = ma

in this case the acceleration is centripetal

            a = v² / r

the linear and angular variable are related

           v = w r

we substitute

           a = w² r

force is the universal force of attraction

           F = G \frac{m M}{r^2}

we substitute

         G \frac{m M}{r^2} = m w^2 r

         w² = \frac{GM}{r^3}

angular velocity is related to frequency and period

         w = 2π f = 2π / T

we substitute

            ( \frac{2\pi }{T} ) = \frac{GM}{r^3}

the final equation is

             T² = ()  r³

b) the speed of the orbit can be found

           v = w r

            v = \sqrt{\frac{GM}{r^3} } \ r

            v = \sqrt{\frac{GM}{r} }

in this case the dependency is the inverse of the root of the distance

Kinetic energy

           K = ½ M v²

           K = ½ M GM / r

           K = ½ GM² 1 / r

the kinetic energy depends on the inverse of the distance

Potential energy

          U =

          U = -G mM / r

dependency is the inverse of distance

Angular momentum

          L = r x p

for a circular orbit

           L = r p = r Mv

           L =

         L =

The angular momentum depends directly on the root of the distance

8 0
3 years ago
A 30.0-μF capacitor is connected to a 49.0-Ω resistor and a generator whose rms output is 30.0 V at 60.0 Hz. (a) Find the rms
Natali5045456 [20]

Explanation:

Given that,

Capacitor = 30μC

Resistor = 49.0Ω

Voltage = 30.0 V

Frequency = 60.0 Hz

We need to calculate the impedance

Using formula of impedance

Z=\sqrt{R^2+X_{c}^2}.....(I)

We need to calculate the value of X_{c}

Using formula of X_{c}

X_{c}=\dfrac{1}{2\pi f c}

X_{c}=\dfrac{1}{2\times\pi\times60.0\times30\times10^{-6}}

X_{c}=88.42\ \Omega

Put the value of X_{c} into the formula of impedance

Z=\sqrt{(49.0)^2+(88.42)^2}

Z=101.08\ \Omega

(a). We need to calculate the rms current in the circuit

Using formula of rms current

I_{rms}=\dfrac{V}{Z}

I_{rms}=\dfrac{30.0}{101.08}

I_{rms}=0.30\ A

The rms current in the circuit is 0.30 A.

(b). We need to calculate the rms voltage drop across the resistor

Using formula of rms voltage

V_{rms}=I_{rms}\times R

Put the value into the formula

V_{rms}=0.30\times49.0

V_{rms}=14.7\ V

The rms voltage drop across the resistor is 14.7 V

(c). We need to calculate the rms voltage drop across the capacitor

Using formula of rms voltage

V_{rms}=I_{rms}\times X_{C}

V_{rms}=0.30\times88.42

V_{rms}=26.53\ V

The rms voltage drop across the capacitor is 26.53 V.

Hence, This is the required solution.

4 0
3 years ago
An ideal gas Carnot cycle with air in a piston cylinder has a high temperature of 1200 K and a heat rejection at 400 K. During t
lana [24]

Answer:

The specific heat capacity is q_{L}=126.12kJ/kg

The efficiency of the temperature is n_{TH}=0.67

Explanation:

The p-v diagram illustration is in the attachment

T_{H} means high temperature

T_{L} means low temperature

The energy equation :

q_{h} = R* T_{h} in(V_{2}/V_{1})

   =0.287 * 1200 ln(3)

   =0.287*1318.33

   =378.36kJ/kg

The specific heat capacity:

q_{L}=q_{h}*(T_{L}/T_{H})

q_{L}=378.36 * (400/1200)

q_{L}=378.36 * 0.333

q_{L}=126.12kJ/kg

The efficiency of the temperature will be:

n_{TH}=1 - (T_{L}/T_{H})

n_{TH}=1-(400/1200)

n_{TH}=1-0.333

n_{TH}=0.67

4 0
3 years ago
A car moves 50km in the first 30 minutes and 50km in the second 30 minutes and continues in this way which motion is this ------
egoroff_w [7]

Answer:

Uniform rectilinear movement (m. r. u.)

Explanation:

It is a continuous movement without acceleration, that is, it moves at a constant speed. The speed does not change over time, for this reason, there is no change in acceleration.

Vf = final velocity = 50/30 [km/s] = 1.67 [km/s]

Vo = initial velocity = 50/30 [km/s] = 1.67 [km/s]

3 0
3 years ago
Other questions:
  • Which of the following characterizes the particles in this diagram?
    9·1 answer
  • The time a basketball player spends in the air when shooting a basket is called the​ "hang time." the vertical leap l measured i
    7·1 answer
  • A(n) __________ is a gravitationally curved path that a celestial body travels around a point in space. A(n) __________ is a gra
    9·1 answer
  • At what age can a child begin to form large concepts such as objects, people, animals, and events?
    12·1 answer
  • If you adjusted the frequency to be lower than the resonant frequency, would the voltage have been leading ahead of or lagging b
    14·1 answer
  • Please can you tell me any current topics in psychology for a project​
    12·2 answers
  • Convert 180 km/h to m/s using dimensional analysis.
    6·1 answer
  • A proton is traveling to the right at 2.0 * 107 m/s. It has a head on perfectly elastic collision with a carbon atom. The mass o
    9·2 answers
  • two identical steel balls mounted on wooden posts initially have different amounts of charge, one -14цC and the other +2цC. the
    8·1 answer
  • a) A bus of mass 760 kg requires 120 m to reach certain velocity value Vf. Ignore friction and drag forces and assume the bus en
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!