B) The amount of work done
Answer:
c. 3/2 mg
Explanation:
Given that the acceleration of an elevator is 1/2 g upward.
The reading on the scale of the elevator is the net external force acting on the elevator.
Let the force F acting on the elevator as shown,
By using Newton's 2nd law, 
where, 
is the net force acting on the elevator.
m is the mass of the elevator,
a is the acceleration of the elevator, as given a=1/2 g upward.
So, 
So, the reading on the scale in the elevator is 
.
Hence, option (c) is correct.
Answer:
The correct option is: d. Fiber-optic
Explanation:
A fiber-optic cables or an optical-fiber cable is a cable that is composed of a bundle of optical fibers. These cables are used for transmitting information or digital signals over long distances.
Each optical fiber in an optical-fiber cable is individually coated with a protective plastic cover and contained in a protective tube. Therefore, an optical-fiber cable is not affected by any electromagnetic interference or radio frequency interference.
Answer:
Vf = 44.27 m/s
Explanation:
When a ball is dropped it is acted upon by gravitational force under free fall motion. So, in order to find its final speed we use 2rd equation of motion, as follows:
2gh = Vf² - Vi²
where,
g = acceleration due to gravity = 9.8 m/s²
h = height lost = 100 m
Vf = Final Velocity = ?
Vi = Initial velocity = 0 m/s (Since, ball starts from rest)
Therefore,
(2)(9.8 m/s²)(100 m) = Vf² - (0 m/s)²
Vf = √(1960 m²/s²)
<u>Vf = 44.27 m/s</u>
Answer:
<em>Gravitational</em><em> force</em>
Explanation:
............
