A woman stands on a scale in a moving elevator. Her mass is 61.0 kg, and the combined mass of the elevator and scale is an addit
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Answer:
a) in the upper position. b) in the lower position. c) in the lower position. d) in the upper position. f) Its kinetic and potential energy will be 0, but the energy is transferred to the element or body that stopped the movement of the pendulum
Explanation:
In the attached image we have the sketch of a pendulum system.
A) The potential energy is maximum when the pendulum is in the upper position (image, fig 1) because the elevation (h) is maximum with respect to the reference point.
B) the potential energy is minimum when the pendulum is in the lower pasition (image, fig 2) because the elevation (h) is cero with respect to the reference point.
Note: When the pendulum is coming down the potential energy is transforming in kinetic energy.
C) The kinetic energy is maximum when the pendulum is in the lower position (image, fig 2), because the potential energy has been transformed in kinetic energy.
D) The kinetic energy is maximum when the pendulum is in the upper position (image, fig 1) because at this moment the pendulum is at rest it means its velocity is 0. We know that the kinetic energy depends on the velocity.
f) The energy is transferred to the element or body that stopped the movement of the pendulum
Define an x-y coordinate system such that
The positive x-axis = the eastern direction, with unit vector
.
The positive y-axis = the northern direction, with unit vector
.
The airplane flies at 340 km/h at 12° east of north. Its velocity vector is
The wind blows at 40 km/h in the direction 34° south of east. Its velocity vector is
![\vec{v}_{2} =40(cos(34^{o})\hat{i} - sin(24^{o})]\hat{j}) = 33.1615\hat{i} -22.3677\hat{j})](https://tex.z-dn.net/?f=%5Cvec%7Bv%7D_%7B2%7D%20%3D40%28cos%2834%5E%7Bo%7D%29%5Chat%7Bi%7D%20-%20sin%2824%5E%7Bo%7D%29%5D%5Chat%7Bj%7D%29%20%3D%2033.1615%5Chat%7Bi%7D%20-22.3677%5Chat%7Bj%7D%29)
The plane's actual velocity is the vector sum of the two velocities. It is
The magnitude of the actual velocity is
v = √(121.1615² + 306.0473²) = 329.158 km/h
The angle that the velocity makes north of east is
tan⁻¹ (306.04733/121.1615) = 21.6°
Answer:
The actual velocity is 329.2 km/h at 21.6° north of east.
The positive x-axis = the eastern direction, with unit vector
The positive y-axis = the northern direction, with unit vector
The airplane flies at 340 km/h at 12° east of north. Its velocity vector is
The wind blows at 40 km/h in the direction 34° south of east. Its velocity vector is
The plane's actual velocity is the vector sum of the two velocities. It is
The magnitude of the actual velocity is
v = √(121.1615² + 306.0473²) = 329.158 km/h
The angle that the velocity makes north of east is
tan⁻¹ (306.04733/121.1615) = 21.6°
Answer:
The actual velocity is 329.2 km/h at 21.6° north of east.