A parachute is driven toward east direction with a speed of 20ms-1. A ball is thrown out with the speed of 4ms-1. What wil be the speed of the ball after it has been thrown out of parachute.

24

Explanation:

Well I'm not sure, but if I understand it right, the answer should be 24ms-1, downwards.

Well in short,

Since you're going down at 20ms-1 holding the ball in your hand, that means the ball is also falling at 20ms-1 right? Make sense right? Ya

Cuz i thing in motion stays in motion unless a force is acted upon it

So let's say the person just let go of the ball, it will be 20m/s, but since the question said he threw it with a speed of 4m/s, that means the speed is

20 +4 = 24m/s

the answer is a. at the equator

  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