Answer:
(a) The elevator has an acceleration of 2.14 m/s² and direction is downward
(b) The acceleration is a=2.14 m/s²
Explanation:
Let +y be upward direction
For Part (a)
The mass of student (whose weight is 550N) is:
ms=w/g
ms=550/9.8=56.1 kg
Apply ∑Fy=ma

Solve for acceleration a

The elevator has an acceleration of 2.14 m/s² and direction is downward
Part(b)
For the acceleration is the scale reads 670 N
For n=670N
So

Answer:
discount rate
Explanation:
i could be wrong but i believe thats what it is
Answer:
The speed maximum speed is 
Explanation:
The centrifugal force always acts on the cylinder and move away the rotating platform from the rotational axis. so the centripetal force provide by the frictional force:
Therefore
coefficient of static friction: 
mass of the cylinder:
\
distance of the cylinder from the turntable: 

cross multiply to find v

Answer:
B
Explanation:
option b stands for less down and cm is less than km
Yo sup??
the 1st, 3rs and 4th statement are true because electromagnetic waves can travel large distances and electromagnetic waves are visible (only 400-700 nm wavelenght)
Hope this helps