Just divide the both, you will get the answer!
does it sound rude?
im sorry for that!
Answer:
no material that were once part of living things
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:
Masa, m = 0.088 kg
Explanation:
Given the following data;
Temperatura inicial = 30°C
Temperatura final = 120°C
Capacidad calorífica específica = 138J/kg.K
Calor absorbido, Q = 4400 cal.
Para encontrar la masa;
La capacidad calorífica viene dada por la fórmula;
Dónde;
Q representa la capacidad calorífica o la cantidad de calor.
m representa la masa de un objeto.
c representa la capacidad calorífica específica del agua.
dt representa el cambio de temperatura.
dt = T2 - T1
dt = 120 - 30
dt = 90°C to kelvin = 273 + 90 = 363K
Sustituyendo en la fórmula, tenemos;
Masa, m = 0.088 kg
Answer:
356 000 J
Explanation:
Total Energy released
= Energy released when water cools to 0 + Energy released when water is converted to ice at 0
= mcT + ml
= (0.5)(4200)(90-0) + (0.5)(334 000)
= 189 000 J + 167 000 J
= <u>3</u><u>5</u><u>6</u><u> </u><u>0</u><u>0</u><u>0</u><u> </u><u>J</u>