Friends tell you that on a recent trip their average velocity was +20 m/s. Is it possible that at any time during their trip their velocity was -20 m/s? Explain, and give an example to justify your answer. PLEASE HELP

Yes. Please find the answer in the explanation.

Explanation:

Yes. Since velocity is a vector quantity, that is, it has both magnitude and direction.

If the displacements covered are not of the same direction, the velocity will not also of the same direction.

Take for instance, if the velocity in a positive is 40 m/s and velocity in the opposite direction is - 20 m/s . Then, the resultant velocity will be 40 - 20 = 20 m/s

Therefore,  it is possible that at any time during their trip their velocity was -20 m/s.

  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

less than one you can't create energy