Lorentz transformation (cf. probs. 1.6.19+21 in textbook) an observer standing on earth observes spaceship travel (a) two spaceships are heading in the same direction toward earth, one at vi-0.95c and the other one at v2-0.85c relative to earth. what is the speed of spaceship- 1 as seen from the captain in spaceship-2? (b) two other spaceships are heading toward earth from opposite directions, at speeds of vz-0.8c and va-0.9c relative to earth. what is the speed of spaceship- 4 as seen from the captain in spaceship-3? (c) if spaceship-1 is 0.3ly (1 ly-1 lightyear, the distance light travels in one year) away from earth, how much older (in seconds) will be: (i) the observer, and (ii) the captain, once the spaceship has landed on earth?

  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

where are the vectors ?

electrical potential energy =0.072 j

explanation:

electrical potential energy is given by

u= q δv

q= charge=6 c

δv= potential difference and is given by

δv= e d

e= electric field

d= distance=5 mm=0.005 m

δv=2.4 (0.005)=0.012 v

now electric potential energy= u= q δv

u=6 (0.012)

u=0.072 j