Answer:
Weight needed to balance the bar is 
Explanation:
Given the weight of the bar is 
The length of the bar is 
The weight of the bar will be uniformly distributed over the entire span. We will consider this as a point load acting in the middle of span length, which is at a distance of
from both ends.
Now applying momentum equation about balanced load we get, (see attachment)

Answer:6amperes
Explanation:
1/R=1/40 + 1/40
1/R=2/40
Cross multiplying we get
2R=40
Divide both sides by 2
2R/2 =40/2
R=20ohms
Current=voltage ➗ resistance
Current=120 ➗ 20
Current =6amperes
هفلونهتررغفببذاراتتتااتاتععتتتتتننهننهلبا
The speed of a sound wave does not depend on the frequency of the wave, but only on the properties of the medium.
Since we are in the same concert all, the medium of propagation is still the same (the air), so it has not changed; therefore, the speed of the sound wave has not changed, and it is still 344 m/s.
So, the correct answer is "344 m/s".