Dentists' chairs are examples of hydraulic-lift systems. If a chair weighs 1400 N and rests on a piston with a cross-sectional area of 1220 cm2, what force must be applied to the smaller piston with a cross-sectional area of 72 cm2 to lift the chair?

The magnitude of force to be applied on the smaller piston for lifting the chair is of 82.62 N.

Given data:

The weight of Chair is, W = 1400 N.

The cross - section area of larger piston is, A = 1220 cm².

The cross - section area of smaller piston is, a = 72 cm².

The given problem is based on the concepts of Pascal's law, which says that the pressure applied at any one point on the walls of vessel, gets equally distributed throughout the vessel.

Therefore,

P  = p

Here, P is the pressure on larger section and p is the pressure on smaller piston.

So,

W/A = f/a

Solving as,

1400/1220 = f / 72

f = 1400/1220 × 72

f = 82.62 N

Thus, we can conclude that the magnitude of force to be applied on the smaller piston for lifting the chair is of 82.62 N.

Learn more about the Pascal's law here:

link

Force applied to smaller cross section is

= 82.63 N

Explanation:

As we know

where signifies the weight of the two chair in a hydraulic-lift system

And signifies the area of the two respective chairs in a hydraulic-lift system

Given -

N

Square centimeter

Square centimeter

Substituting the given values in above equation, we get -

Force applied to smaller cross section is

= 82.63 N

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.

b.

hope this : )