Avan slows down as it travels up a steep hill. its speed goes from 20m/s at the bottom of the hill to 12m/s when it reaches the top 8 seconds later. how far has the van travelled between the bottom and the top of the hill?

Answer

13.06 m

Explanation

The height reach ca be calculated using the one of the linear equation.

v² = u² - 2gs

where u ⇒ is the initial speed,

          v ⇒ is the final speed

        g ⇒ is the acceleration due to gravity and

       s ⇒ the height reached.

v² = u² - 2gs

12² = 20² - (2×9.8×s)

144 = 400 - 19.6s

19.6s = 400 - 144

        = 256

s = 256/19.6

    = 13.06 m

d = 128 m

Explanation:

Here given that van slows down as it travels up a inclined steep hill

So here we can assume that through out the motion its acceleration will remain constant.

Now we can use kinematics to find out the distance traveled by it

As we know that acceleration is defined as

here we know that

time = 8 s

now we have

Now in order to find out the distance it moved we can use

now we will plug in all above data

so it will cover total distance of 128 m

  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