A-LEVEL PHYSICS: 4.4.3: Newton's Third Law (SaveMyExams)

Question 1

Newton’s First & Second Laws of Motion deal with ___ ___ acting on a single object.

Answer 1

Multiple Forces.

Question 2

Newton’s Third Law deals with the Forces involved when…

Answer 2

Two objects interact.

Question 3

Newton’s Third Law:

Answer 3

If object A exerts a Force on object B, object B will exert a Force on object A which is Equal in Magnitude, but Opposite in Direction.

Question 4

When two objects interact, the Forces involved arise in ___, usually referred to as…

Answer 4

Pairs, Newton’s Third Law Pairs.

Question 5

A Newton’s Third Law Pair must be: (4)

Answer 5

-Same Type of Force

-Equal in Magnitude

-Opposite in Direction

-Acting on Different Objects

Question 6

What is the Newton’s Third Force Pair involved when walking? (2)

Both of these Forces are… (2)

Answer 6

-Force of Foot on Ground.

-Force of Ground on Foot (Equal in Magnitude, Opposite in Direction)

Both of these Forces are:
-Normal Contact Forces
-Acting on Different Objects

Question 7

Explain, in terms of the Newton’s Third Law Force Pairs involved, a book on a table. Justify why they are Force Pairs.
(4)

Answer 7

-Force of Book on Table.
-Force of Table on Book.

Why this is a NIII Force Pair:
-Equal in Magnitude, Opposite in Direction. -Same Type of Force: Both are Normal Contact Forces.

-Force of Earth Pulling the Book.
-Force of Book Pulling the Earth.

Why this is a NIII Force Pair:
-Equal in Magnitude, Opposite in Direction.
-Same Type of Force: Both are Weight Forces
(The Gravitational Pull of the Earth on the Book, & the Gravitational Pull of the Book on the Earth)