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Tema [17]
2 years ago
10

An elevator is being lowered at steadily decreasing speed by a steel cable attached to an electric motor. There is no air resist

ance, nor is there any friction between the elevator and the walls of the elevator shaft. Why does the upward force exerted on the elevator by the cable have a larger magnitude as the downward force of gravity on the elevator
Physics
2 answers:
shtirl [24]2 years ago
6 0

Answer:

F = W + ma  a> 0

Explanation:

For this exercise let's use Newton's second law

 we assume the upward direction as positive

          F - W = m a

          F = W + ma

          F = m (g + a)

In this case they indicate that the speed is less and less as it goes down, therefore the acceleration must be opposite to the speed, that is, the acceleration is upwards, consequently it is positive

               

We can see that since a> 0 the force F must have greater than the weight of the elevator

Anvisha [2.4K]2 years ago
6 0

Answer:

Please see below as the answer is self-explanatory.

Explanation:

  • At any time, there are two forces acting on the elevator: the tension in the cable T (upward) and the force of gravity (downward).
  • Taking the upward direction as positive, if we apply Newton's 2nd law, we will have the following equation:

       T - m*g = m*a (1)

  • Now, we know that the elevator is being lowered at a decreasing speed, which means that the acceleration must have an opposite direction to the displacement.
  • Since the displacement is downward, that means that the acceleration must be positive.
  • If a ≥ 0, this means that T- mg ≥ 0, so the tension T must have a larger magnitude as the downward force of gravity on the elevator.
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Answer:

The center of mass of the Earth–Moon system is 4.613 × 10⁶ m from center of the Earth.

Explanation:

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X_{Cm = \frac{M_eX_e +M_mX_m}{M_e+M_m}

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Me is the mass of the Earth = 6 × 10²⁴ kg

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3 years ago
Arrange the following events in the mantle convection process. Use numbers 1-5.
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Answer:

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3 years ago
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Answer:

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Explanation:

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Q=CV\\Q=23*3.363*10^{-12}\\ Q=7.73*10^{-12}\\ Q=77.3pC

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