Answer:
a. 16 s b. -1.866 kJ
Explanation:
a. Since the initial rotational speed ω₀= 3313 rev/min = 3313/60 × 2π rad/s = 346.94 rad/s. Its rotational speed becomes ω₁ = 0.75ω₀ in time t = 4 s.
We find it rotational acceleration using α = (ω₁ - ω₀)/t = (0.75ω₀ - ω₀)/t = ω₀(0.75 - 1)/t = -0.25ω₀/t = (-0.25 × 346.94 rad/s)/4 s = -21.68 rad/s².
Since the turntable stops at ω = 0, the time it takes to stop is gotten from
ω = ω₀ + αt and t = (ω - ω₀)/α = (0 - 346.94 rad/s)/-21.68 rad/s² = (-346.94/-21.68) s = 16 s.
So it takes the turntable 16 s to stop.
b. The workdone by the turntable to stop W equals its rotational kinetic energy change.
So, W = 1/2Iω² - 1/2Iω₀² = 1/2 × 0.031 kgm² × 0² - 1/2 × 0.031 kgm² × (346.94 rad/s)² = 0 - 1865.7 J = -1865.7 J = -1.8657 kJ ≅ -1.866 kJ
Answer: this isnt really helping me
Explanation:
145,600 it equals 145,600 so you put down the zeros
Answer:
-0.481 m/s^2
Explanation:
The force equation of this problem is given as:
F - W = ma
where F = upward force holding the clarinet bag
W = downward force (weight of the clarinet)
The mass of the clarinet bag is 3.010 kg, therefore, its weight is:
W = mg
W = 3.010 * 9.8 = 29.498
F = 28.05 N
Therefore:
28.05 - 29.498 = 3.010 * a
-1.448 = 3.010a
=> a = -1.448 / 3.010
a = -0.481 m/s^2
The acceleration of the bag is downward.
Answer:
The atmospheric pressure and boiling point are directly proportional
Increasing atmospheric pressure increases the boiling point also
Explanation:
The atmosphere contain molecules that are in constant motion. They exert a downward force on a liquid’s surface. The higher the air pressure, the harder it is for the liquid to evaporate. Therefore, the boiling point of a solvent or liquid is affected by the atmospheric pressure and boiling point is raised.
A liquid in a high pressure environment boils at a higher temperature.
When placed in a lower pressure environment it boils at a lower temperature.
