9.3- CONSERVATION OF MOMENTUM

Question 1

What is Newton’s third law of motion?

Answer 1

when two objects interact, they exert equal + opposite forces on each other

Question 2

What must apply for forces to be considered a force pair?

Answer 2

two forces must be of same type, + acting on different objects

Question 3

What changes when an object is acted on by a resultant force?

Answer 3

its momentum changes

Question 4

What can there not be if there in no change in momentum of an object?

Answer 4

can be no resultant force on object

Question 5

How can momentum be transferred?

Answer 5

interactions between objects

Question 6

Does the total momentum of objects change when they interact?

Answer 6

no

Question 7

What does the principle of momentum state?

Answer 7

for a system of interacting objects, total momentum remains constant, provided no external resultant force acts on system

Question 8

What happens to momentum when two object collide with each other and then separate?

Answer 8

momentum of each object changes

Question 9

What do two objects that collide with each other then separate exert when they are in contact?

Answer 9

exert equal + opposite forces on each other when they’re in contact

Question 10

When two objects collide with each other then separate, what is the change in momentum of one object equal to?

Answer 10

equal + opposite to change of momentum of other object

Question 11

When two objects collide with each other then separate, if one object gains momentum, what happens to the other objects and what is total momentum like?

Answer 11

loses equal amount of momentum

total amount of momentum unchanged

Question 12

What is final momentum equal to?

Answer 12

initial momentum

Question 13

If colliding objects stick together as a result of collision, what are their final velocities like?

Answer 13

have same final velocity

Question 14

Testing conservation of momentum?

Answer 14

using motion sensor linked to computer
mass of each trolley measured before test
trolley B at rest, trolley A given push so it moves towards trolley B at constant velocity
computer records + displays velocity of trolley A throughout this time

Question 15

What does the computer show the velocity of trolley A to be like? (testing conservation of momentum)

Answer 15

velocity of trolley A dropped suddenly when impact took place

Question 16

What can be used instead of a motion sensor? (testing conservation of momentum)

Answer 16

light gates linked to computer or data logger

Question 17

How is the experiment done when light gates are used? (testing conservation of momentum)

Answer 17

card attached to trolley A passes through first of two light gates
trolley B positioned so A collides with it just after passing through first light gate

Question 18

How is the velocity of A before the collision calculated when using light gates? (testing conservation of momentum)

Answer 18

dividing card length by time taken to pass through first gate

Question 19

How is the velocity of A after the collision calculated when using light gates? (testing conservation of momentum)

Answer 19

dividing card length by time taken to pass through second gate

Question 20

When two objects moving in opposite directions collide with each other, what does it depend on for the collision to cause the two objects to stop?

Answer 20

mass + initial velocities of the two objects

Question 21

If two objects moving in opposite directions collide with each other and come to a stop, what does this do to momentum?

Answer 21

momentum of two objects after collision would then be zero

Question 22

How is the vector nature of momentum taken into account, when two objects are moving in opposite directions?

Answer 22

by assigning numerical values of velocity + or - according to the direction