July 13th, 2013 — Automotive

An automotive LIFOtraisese a 3500lb car 7ft above floor level if the hydraulic cylinder contain 8in diameter piston and a 4in diameter rod,determine the

A. work necessary to lift the car

B. required pressure

C. power if the lift raises the car 10 s

D. Descending speed of the lift for a 10-gpm flow rate

E. flow rate for the auto too descend in 10 s

### Chosen Answer:

All these answers based on 8 inch lifting cylinder. You haven’t specified anything about the 4 inch rod so haven’t used that in these answers

a). work = force x distance

work = 3500 lb x 7 ft = 24,500 ft-lbs of work

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b) 8 inch diameter piston = area of pi * r^2 = 50.26 sq inches

3500 lb / 50.26 in^2 = 69.6 psi pressure

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c) power = work / time = 24,500 ft-lbs / 10s = 2450 ft-lb/ second

(one foot-lb /second = 0.738 watt so –> 2450 * .738 = 1,808 watts of power in SI system)

—————————————————————-

d) volume of a cylinder = pi * radius squared * height

one gallon = 231 cubic inches

10 gallons = 2,310 cubic inches

V =2,310 cubic inches = 3.14 * 4in ^2 * height

height = 2310 / (pi * 16) = 45.96 inches

So 10 gallons a minute will lift car or descend car 45.96 inches or 3.8 feet a minute

————————————————————————————————–

e) Flow rate to descend in 10 seconds instead of a minute is 6 times faster (60 sec a minute / 10 sec) = 6.

6 * 10gpm = 60 gpm

.

by: biire2u

on: 14th April 10

April 24th, 2013 — Automotive

Painting and plastering is important to the look of a home. A good paint job raises the value of the home or business. One thing that many people must understand is that painting is more than just stroking the brush to cover areas on a wall. It’s much more than that. Care and meticulousness must be added to ensure that a good paint job is done. A good painter should also be fully licensed and insured. This protects the homeowner from any damage that is made by the painter or the painter’s crew. Painting is dangerous work. Painters deal with the fumes and solvents that could cause severe bodily harm. Proper measures should be implemented to ensure that they are not hurt. While it is necessary to have a skill set as painting, they must also ensure that they are protected and their client’s home is protected.

Good painting contractors in Long Island are hard to come by, but they are there. They should be diverse in their field, not only knowing how to paint and paint well, but follow safety standards, supervise other workers and be creative on the job. Good painting contractors in Long Island should also have a good understanding of plastering and staining. Painting is a multidimensional job and a quality contractor will know how to attack a space and attack it well.

The most important aspect of finding a good painting contractor in Long Island is whether or not they offer warranties. A warranty is a sign that they are out to achieve the best possible result.

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Posted:

February 6th, 2012 — Automotive

1) what’s the kinetic energy of a 2kg toy car moving at a velocity of 5 m/s?

A. 5 J

B. 10 J

C. 25 J

D. 50 J

2) a 50 kg firefighter is on a ladder 10 meters above the ground. when the firefighter descends to 5 meters above the ground, the firefighter’s gravitational potential energy will decrease by

A. 0.194 joules

B. 5.10 joules

C. 490 joules

D. 2450 joules

3)a hydraulic lift used at an automotive repair shop raises a 1000 kg car two meters off of the ground. what is the potential energy given to the car?

A. 1000 J

B. 2000 J

C. 9800 J

D. 19,600 J

4) a 5 kg mass is lifted from the ground to a height of 10 meters, the gravitational potential energy of the mass is increased by approximately

A. 0.5 J

B. 50 J

C. 250 J

D. 500 J

5) a high diver steps off a diving platform that is 10 meters above the water. if no air resistance is present, during the fall there will be a decrease in the diver’s

A. gravitational potential energy

B. total mechanic energy

C. kinetic energy

D. momentum

### Chosen Answer:

1. C kinetic energy = i/2 mass (velocity)2

2.D gravitational potential energy is =mgh where m = mass,g= 9.8m/s2 and h is height it descends to 5 that’s why the answer is 2450J

3.answer is letter D 19600J the formula is P.E = mgh

4.the answer is letter D value of g varies other use the original value 9.8 m/s2 while Other can also use 10m/s2 in case of number the value use is 10m/s2.

5. A

by: len

on: 4th May 09