You drive your car from home at an
average velocity of 80 km/h for 3 h.
halfway to your destination, you develop
soine engine problems, and for 5 h you
nurse the car the rest of the way. what is
your average velocity for the entire trip?

60 km/h

Explanation:

In the first part of the trip, the speed is

v = 80 km/h

while the time interval is

t = 3 h

So, the distance covered is:

d = vt = (80)(3)= 240 km

The problem states that this distance is half distance between home and the destination - so, the total distance between home and the destination is

The time taken to cover the second part of the trip is 5 h, so the total time taken is

T = 3 h + 5 h = 8 h

Therefore, the average velocity for the entire trip is

  1.the balanced   chemical equation is as below

cu +   2 ag(no)₃ → cu(no₃)₂   +2 ag

2.the   much silver   produced   is   50.9 g

step 1: find the   moles of cu

moles =   mass÷   molar mass

  from periodic table the molar mass of cu = 63.5 g/mol

moles is therefore = 15.00 g÷ 63.5 g/mol = 0.236   moles

step 2: use the mole ratio to determine the   moles of ag

from equation above   cu: ag   is 1: 2

therefore the moles of ag   =0.236   moles   x 2/1 =0.472   moles

step 3: find the mass   of ag

mass = moles x molar mass

from periodic table   the molar mass of ag =107.87 g/mol

mass   = 0.472   moles x 107.87 g/mol = 50.9 g

3.   the   much   silver   collected worth is   1.797 oz

  convert   50.9 g   to oz

that is   1 gram = 0.0353 oz

          50.9 grams =?   oz

by cross multiplication

={(50.9 grams x 0.0353 oz) / 1   gram}   =1.797 oz

the independent variable, or the one that is intentionally manipulated is the speed.