Answer:
t=2s
Explanation:
The definition of power is:

And the work-energy theorem states that:

Since the movement starts from rest, we have that:

And putting all together:

Since we want the time taken:

Which for our values is:

Answer:
Part a)

Part b)

Part c)

Part d)
from t = 0 to t = 4.9 s
so the reading of the scale will be same as that of weight of the block
Then its speed will reduce to zero in next 3.2 s
from t = 4.9 to t = 8.1 s
The reading of the scale will be less than the actual mass
Explanation:
Part a)
When elevator is ascending with constant speed then we will have



So it will read same as that of the mass

Part b)
When elevator is decending with constant speed then we will have



So it will read same as that of the mass

Part c)
When elevator is ascending with constant speed 39 m/s and acceleration 10 m/s/s then we will have



Reading is given as



Part d)
Here the speed of the elevator is constant initially
from t = 0 to t = 4.9 s
so the reading of the scale will be same as that of weight of the block
Then its speed will reduce to zero in next 3.2 s
from t = 4.9 to t = 8.1 s
The reading of the scale will be less than the actual mass
Answer:
The mass of Ar is 36.91g
Explanation:
The gas mixture consist of Neon(Ne) and Argon(Ar)
Partial pressure of Ar = total pressure of mixture - partial pressure = 4 - 0.3 = 3.7 atm
Mole fraction of Ar = partial pressure of Ar ÷ total pressure of mixture = 3.7/4 = 0.925
Mass of Ar = 0.925 × molecular weight of Ar = 0.925 × 39.9 = 36.91g
I believe the answer is c but I’m not 100% sure
The answer is Marie Skłodowska Curie (AKA Marie Curie). She <span>lived her life awash in ionizing radiation. She would be carrying bottles of the radium and polonium in the pocket of her coat and put them in her desk drawer.
So even after a century, her papers are still radioactive. Since the</span><span> most general isotope of radium, which is radium-226, has a half life of 1,601 years.</span>