1 - Momentum

Question 1

Physics Principles -

0 Uniform Motion

Answer 1

NEWTON’S FIRST LAW

F net = 0 - objects in motion stay in motion unless acted upon by an external net force

Question 2

Physics Principles -

1 Accelerated Motion

Answer 2

NEWTON’S SECOND LAW

F net does not equal 0 - an external non-zero force acting on an object equals to its mass x acceleration

Question 3

Physics Principles -

5 Conservation of Energy

Answer 3

Deals with kinetic energy

Question 4

How Do Force and Time Affect Momentum? (Objects Landing On Harder Surfaces / Landing On Softer Surfaces)

Answer 4

Harder landing surface - (a)
More cushioned landing surface - (b)

Vi (a) = x = Vi (b) 
Vf (a) = 0 = Vf (b)
t (a) < t (b) 
d (a) < d (b)
F (a) > F (b) 
p (a) = p (b)

Question 5

What Is The Area Under a Net Force As a Function Of Time Graph?

Answer 5

Impulse (a change in momentum)

△p = m△v

△p = F△t

Question 6

How Are Impulse And Momentum Related?

Answer 6

Impulse is a change in momentum.
p=mv
△p = m△v = F△t

Question 7

What Is The Effect On Impulse If….

a) The Time Interval Doubled?
b) The Net Force Is Reduced To 1/3 Of Its Original Magnitude

Answer 7

a) Impulse is doubled

b) Impulse is reduced to 1/3

Question 8

Two Masses In a Collision Experience The Same Or Different…

a) Force
b) Impulse
c) Velocity

Answer 8

a) Same
b) Same
c) Same

Question 9

What Is A System?

Answer 9

A group of two or more objects that interact.

Question 10

Physics Principle -

4 Conservation of Momentum

Answer 10

The total momentum within a system is constant.

Momentum is always conserved.

☆Only deals with isolated systems

Question 11

Conservation of Momentum in 2 Dimensions

Answer 11

Divide into horizontal vectors (pi x = pf y) and vertical vectors (pi y = pf y)

Then use a ² + b ² = c ² (px ² + py ² = p ² ) to find the resultant p

Question 12

Conservation of Momentum in 1 Dimension

1) Masses Rebound
2) Stick Together
3) Explosion

Answer 12

1) m₁v₁ i + m₂v₂ i = m₁v₁ f + m₂v₂ f
2) m₁v₁ i + m₂v₂ i = (m₁ + m₂)v f
3) 0 = m₁v₁ i + m₂v₂ i

☆The = sign is the event

Question 13

What Are The Units For Impulse?

Answer 13

△p =
F△t = m△v
N⋅s = kg⋅m/s²

Question 14

What Does It Mean When Momentum Is Conserved?

Answer 14

The total momentum of the two objects before the collision is the same as the total momentum after the collision.

p i = p f
p sys i = p sys f
(where (F net)sys = 0)
☆only deals with isolated systems

Question 15

Whats An Isolated System?

Answer 15

There’s no external forces acting upon the object

Question 16

Whats a Non-Isolated System?

Answer 16

There’s and external force acting upon the object

Question 17

Whats An Elastic System?

Answer 17

Ek i = Ek f

The total kinetic energy of the system is 0

Question 18

Whats An Inelastic System?

Answer 18

Ek i ≠ Ek f

The total kinetic energy is not conserved

When two objects stick together in a collision it is inelastic