Decision Making - - Hydraulic jack

Diagram shows a hydraulic jack in a car service centre.

Table below shows four type of hydraulic oil, K, L, M and N , with different specifications. You are required to determine the most suitable hydraulic oil to run the hydraulic jack.

Study the specifications of all four types of hydraulic oil from the following aspects:

i ) Boiling point of the hydraulic oil

ii) Specific heat capacity of the hydraulic oil

iii) Density of hydraulic oil

iv) Rate of vaporisation of hydraulic oil

Suggested answer:

i) Has high boiling point

~ so that hydraulic fluid not easily boiling

ii) Has higher specific heat capacity

~ so that it can't be easily became hot

iii) Has lower density

~ so the hydraulic oil is not heavy

iv) Has lower rate of vaporisation

~ Volume of the hydraulic oil not easily vaporise.

Hydraulic oil L is chosen

Reason :

L has high boiling point, higher specific heat capacity, lower density and lower rate of vaporisation .