Answer:
The elevator must be moving upward.
Explanation:
During the motion of an elevator, the weight of the person deviates from his or her actual weight. This temporary weight during the motion is referred to as "Apparent Weight". So, when the elevator is moving downward, the apparent weight of the person becomes less than his or her actual weight.
On the other hand, for the upward motion of the elevator, the apparent weight of the person becomes more than the actual weight of that person.
Since the apparent weight (645 N) of the student, in this case, is greater than the actual weight (615 N) of the student.
<u>Therefore, the elevator must be moving upward.</u>
Answer:
T_ac = 6.586 KN
R = 10.51 KN
Explanation:
Given:
- Tension in cable T_ab = 9.1 KN
Find:
- Determine the required tension T in cable AC such that the net effect of the two cables is a downward force at point A
- Determine the magnitude R of this downward force.
Solution:
- Compute the three angles as shown in figure attached, a, B , y:
a = arctan (40/50) = 38.36 degrees
B = arctan (50/30) = 59.04 degrees
y = 180 - 38.36 = 82.6 degrees
- Use cosine rule to calculate R and F_ac as follows:
sin(a) / T_ac = sin(B) / T_ab = sin(y) / R
sin(38.36) / T_ac = sin(59.04) / 9.1 = sin(82.06) / R
T_ac = 9.1 * ( sin(38.36) / sin(59.04) )
T_ac = 6.586 KN
R = 9.1 * ( sin(82.06) / sin(59.04) )
R = 10.51 KN
<span> Magnetic fields have north and south magnetic poles.</span>
To solve this problem we will use the concepts related to the speed of a string which is given by the applied voltage and the linear mass density of it. With the speed value we can find the fundamental frequency that will serve as a step to find the maximum speed through the relation of Amplitude and Angular Speed. So:
Where,
T = Tension
= Linear mass density
With this value the fundamental frequency would be
Finally the maximum speed is given with the relation between the Amplitude (A) and the Angular frequency, then
Therefore the correct answer is B.
