+ 6.3 Quiz (B)
This test/quiz is accepting submissions until Friday, January 29, 2021 at 3:00 pm
Questions 1
Question 1 (1 point)
A roller coaster with a mass of 700 kg has 9000 J of kinetic energy. How fast is going (what is its velocity)?
a
12.85 m/s
b
6.4 m/s
С
5.1 m/s

5.1 m/s

Explanation:

The equation for kinetic energy is KE=1/2m*v2

You plug 9000J into KE and divide 700 in half to plug in for 1/2m.  That gives us 9000=350*v2.  You divide on both sides by 350, leaving us with 25 with a remainder=v2.  The square root of 25 is 5.  5.1.

my exact test question and unit haha

layer a is the exosphere and layer b is the thermosphere.   is the answer i think but i hope this .

  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