Determine- the rates of acceleration and deceleration, max velocity achieved, length of the lift shaft?
Question by Alex Rimmington: Determine- the rates of acceleration and deceleration, max velocity achieved, length of the lift shaft?
A direct drive hoist is initially required to accelerate a load of 1.5 tonne through a vertical distance of 140m in a time of 12 seconds. It then maintains a period of constant velocity for 10.6 seconds before uniform deceleration brings the load to reat at the top of the lift in a time of 15 seconds.
need to find average velocity
Best answer:
Answer by wingstwo
Where v = final velocity, vi = initial velocity, x = distance
Phase 1: Accelerating
x1 = xi + ½(v+vi)·t
140m = 0 + ½(v+0)·12s
v1 = 23 1/3 m/s
also,
v1 = vi + at
23 1/3 m/s = 0 + a1(12)
a1 = 1 17/18 m/s²
Phase 2: Constant velocity
x2 = rate * time
x2 = vt = 23 1/3 m/s²*10.6sec
x2 = 247 1/3 m
Phase 3: Deceleration
v3 = vi + a3·t
0 = 23 1/3 m/s + a3·(15s)
a3= -1 5/9 m/s
x3 = xi + ½(v+vi)·t
x3 = 0 + ½(0+23 1/3 m/s)·15s
x3 = 175m
ANSWERS
1. Max acceleration:
a = 1 17/18 m/s²
2. Max Deceleration:
a= -1 5/9 m/s
3. Max Velocity:
v = 23 1/3 m/s
4. Length of Lift Shaft:
x = 140m + 247 1/3 m + 175m
x = 562 1/3m
5. Average speed = dist/time
= 562 1/3m / (12 + 10.6 + 15) = 14.96 m/s
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Categories: Disability Hoist Hire Tags: acceleration, achieved, deceleration, Determine, length, lift, rates, shaft, velocity
Q&A: Where can I find somewhere that offers holidays for the disabled at discount rates?
Question by Sue R: Where can I find somewhere that offers holidays for the disabled at discount rates?
Does anyone know of any holiday sites/venues that offer discounted rates for disabled people? Of the ones that have been recommended to us in the past, because they are specially adapted for disabled people, it has greatly inflated the price. Hubby is a paraplegic, and having a hoist to get into/out of bed would be a massive help. We haven’t had a holiday for 8 years, and funds are not great, so any ideas would be greatly appreciated
Best answer:
Answer by angie
http://www.direct.gov.uk/en/DisabledPeople/TravelHolidaysAndBreaks/TravelAndHolidaysInTheUk/DG_4015876
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