Determine the lifting time of the elevator in a high-rise building, considering its movement during acceleration
Determine the lifting time of the elevator in a high-rise building, considering its movement during acceleration and deceleration to be equal to alternating with an acceleration equal in absolute value to 1m / s2, and in the middle section – uniform at a speed υ = 2m / s. Elevator lifting height h = 60m.
From the formula for acceleration, we find the acceleration time t₁.
a = (v-v₀) / t₁;
t₁ = (v-v₀) / a = 2 m / s / 1m / s² = 2 s,
where v is the final speed, v₀ is the initial speed.
Acceleration path:
h₁ = at² / 2 = (1m / s² * 4 s²) / 2 = 2 m.
When braking, the initial speed is v, the final speed is 0.
v-at₂ = 0;
Deceleration time t₂:
t₂ = V / a = 2 c;
Braking distance:
h₂ = vt-at² / 2 = 2 m.
Distance when braking and accelerating:
h₁ + h₂ = 2 m + 2 m = 4 m.
Path traveled evenly:
h₃ = h – (h₁ + h₂) = 60 – 4 = 56 m.
Steady motion time:
t₃ = 56 m / 2 m / s = 28 s.
Total time
t = t₁ + t₂ + t₃ = 2 + 2 + 28 = 32 s.
Answer: 32 p.