A position versus time graph is shown: Position vs. Time
1 15
10
10
Time (seconds) ->
Which statement accurately describes the motion of the object in the graph above?
O It is at rest for 3 seconds before moving at constant speed for 10 seconds.
It is at rest for 3 seconds before moving at constant speed for 4 seconds.
Olt is moving from 0 cm to 5 cm at constant speed of 7 cm/s.
O it is moving from 0 cm to 3 cm at a constant speed of 3 cm/s.

    The object moves forward at 5 m/s, stops, and then changes velocity.

Explanation:

With the information given in the question we can graph the points (image attached).

As we can observe, in the first segment of the graph the velocity is increasing linearly (at a constant rate) and is 5 m/s, then in the second segment we can see the position of the object remains the same from second 2 to second 4, which means the object is stopped.

Finally, in the third and last segment, we can observe a change in velocity (at a negative constant rate, because is decreasing), which is decreasing until the object stops.

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

it has to be b, about 97 percent.