What does newton's third law say about why momentum is conserved in collisions?

a. equal forces act in equal times, so the change in momentum for both objects must be equal.
b. unequal forces act in unequal times, so the change in momentum for both objects must be equal.
c. unequal forces act in unequal times, so the change in momentum for both objects must be unequal.
d. equal forces act in unequal times, so the change in momentum for both objects must be equal.

Option (A) is the correct answer.

Explanation:

According to Newton's third law of motion, when force is exerted by one body to second body then the  second body will also exert a force equal in magnitude and opposite in direction on the first body.

For example, when we hit a wall with our leg then the wall also applies a force on our leg and thus, our leg gets hurt.

Hence, we can conclude that newton's third law says that momentum is conserved in collisions because equal forces act in equal times, so the change in momentum for both objects must be equal.

first, consult an activity series chart to determine if al is more reactive than fe. it is, so it will replace the fe. now, one can continue with the problem.

next, make sure you have a correctly balanced equation.

3feo + 2al ==> 3fe + al2o3

now, determine which reactant (feo or al) is in limiting supply.

moles feo present = 125 g x 1 mole/71.8 g = 1.74 moles

moles al present = 25.0 g x 1 mole/26.98 g = 0.927 moles

since from the balanced equation, it take 3 mol feo for every 2 mol al, al will be limiting.

you can determine this simply by dividing moles of each by their coefficient in the balanced equation. for example: 1.74/3 = 0.58 and 0.927/2 = 0.464. al is less, so it is limiting.

finally, using the stoichiometry in the balanced eq. determine mass of fe that can be produced from 0.927 moles of al.

0.927 moles al x 3 moles fe/2 moles al x 55.8 g/mole = 77.6 g

here is table 2-2:

country

percent of eligible voters that voted

rank

united states

44.9%

138

canada

60.1%

107

costa rica

84.6%

14

hungary

66.9%

82

japan

57.0%

118

egypt

27.7%

159

south africa

85.5%

10

ans is no, the data set cannot be plotted as a single circle graph