Awoman stands on a bathroom scale in a motionless elevator. when the elevator begins to move, the scale briefly reads only 0.79 of her regular weight.
(a) calculate the magnitude of the acceleration of the elevator.
(b) find the direction of the acceleration.

Part a)

Part b)

Lift is moving downwards as it is coming with negative sign

Explanation:

As we know that the reading of the scale is equal to the normal force on the woman

So we will have

here we know that

so we will have

Part a)

magnitude of the acceleration of the lift is given as

Part b)

Lift is moving downwards as it is coming with negative sign

science is a systematic and logical approach to discovering how things in the universe work. true to this definition, science aims for measurable results through testing and analysis. science is based on fact, not opinion or preferences. the process of science is designed to challenge ideas through research.

explanation:

  the grams     of oxygen gas   that can be produced     is 20.6   grams of o₂

calculation

2liclo₃ →   2 licl + 3 o₂

step 1:   find the moles of liclo₃

moles = mass÷ molar mass

from periodic table the molar mass of liclo₃ =6.9 +35.5   +(16 x3) =90.4 g/mol

moles=38.7 g÷90.4 g/mol=0.4281   moles

step 2:   use the   mole ratio   to calculate the moles of o2

from equation above, liclo₃: o₂   is 2: 3  

therefore the moles of   o₂=0.4281 moles x3/2 =0.6422   moles

step 3: find mass   of o₂

mass= moles x molar mass

from periodic table the   molar mass of   o₂ = 16 x2= 32 g/mol

mass=0.6422   moles   x   32 g/mol = 20.6 grams of o₂