F.3 Newton’s Laws & Momentum

Practice Worksheet — name: ______________________ date: ____________

Formulas for this topic

Momentum

p = mv

Impulse

F \Delta t = \Delta p

Conservation of Momentum

m_1 u_1 + m_2 u_2 = m_1 v_1 + m_2 v_2

Section A — Multiple choice

A1. A 2 kg ball moving at 3 m/s collides with a stationary 1 kg ball. If they stick together, what is their combined velocity?

A $1\, m/s$
B $2\, m/s$
C $3\, m/s$
D $6\, m/s$

A2. Which law explains why a passenger lurches forward when a bus brakes suddenly?

A Newton's First Law
B Newton's Second Law
C Newton's Third Law
D Hooke's Law

Section B — Short answer

B1. State Newton's Third Law and give an everyday example.

B2. Define momentum and explain why it is a vector quantity.

Answer key

For worked explanations, interactive practice and more free resources, visit www.newtonine.com

Section A

A1: $2\, m/s$

A2: Newton's First Law

Section B

B1: For every action force there is an equal and opposite reaction force. Example: a swimmer pushes water backwards, and the water pushes the swimmer forwards.

B2: Momentum is the product of mass and velocity ( $p = mv$ ). It is a vector because velocity has direction; therefore momentum has the same direction as velocity.