Further Mechanics (Unit 4) Flashcards Preview

Physics > Further Mechanics (Unit 4) > Flashcards

Flashcards in Further Mechanics (Unit 4) Deck (34)
Loading flashcards...
1
Q

Newton’s 1st Law

A

An object remains at rest or in uniform motion unless acted on by a force

2
Q

Newton’s 2nd Law

A

The rate of change of momentum of an object is proportional to the resultant force on it

3
Q

Newton’s 3rd Law

A

When two objects interact they exert equal and opposite forces on each other

4
Q

Force (in terms of momentum change)

A

Force = rate of change of momentum. VECTOR

5
Q

Units of momentum

A

kgms-1

6
Q

Units of rate of change of momentum

A

kgms-2

7
Q

Impulse, I

A

Force x time for which the force acts (F(delta)t)

Hence Impulse = change of momentum. VECTOR

8
Q

Units of Impulse, I

A

Ns or kgms-1

9
Q

Area under a graph of force against time

A

change in momentum ((delta)p) or Impulse I

10
Q

Principle of conservation of linear momentum definition

A

In a collision (or explosion) the total momentum before equals the total momentum after, providing no external forces are acting.

11
Q

Elastic collision definition

A

A collision where kinetic energy is conserved

12
Q

Inelastic collision definition

A

A collision where kinetic energy is not conserved.

Note: Total Energy is still conserved.

13
Q

Angular speed, w

A

angle turned through per second. SCALAR

14
Q

Units of angular speed, w

A

rad s-1

15
Q

Centripetal force

A

Resultant force acting towards the centre of the circular path

16
Q

Conditions for shm (simple harmonic motion)

A
  1. acceleration is proportional to displacement

2. acceleration is in opposite direction to displacement OR acceleration always acts towards the equilibrium position.

17
Q

Relating a= -(2(Pi)f)2 x, to definition of shm

A
  1. acceleration is proportional to displacement
    a directly proportional to x and hence a = kx, where k is a constant (2(Pi)f)2.
  2. acceleration is in opposite direction to displacement
    minus sign indicates that acceleration, a, is in opposite direction to displacement, x.
18
Q

Graph of acceleration against displacement.

A

Gradient = -(2(Pi)f)2

19
Q

Gradient of displacement against time

A

Gradient of a displacement against time graph is velocity

20
Q

Graphical representations linking x, v, a and t

A

Check Sheet

21
Q

Conditions for the time period equation of a pendulum

A

Time Period equation for a pendulum is only true for oscillations with a small amplitude, that is, angular displacements less than 10 degrees.

22
Q

Dependence of time period on amplitude of an oscillation

A

Time period of oscillation in SHM is independent of amplitude.

23
Q

Variation of Ep and Ek with displacement

A

Check Sheet

24
Q

Variation of Ep and Ek with time

A

Check Sheet

25
Q

Resonance definition

A

When the driving frequency equals the natural frequency of an oscillating system, vibrations with large amplitude are produced

26
Q

Free oscillation definition

A

oscillations with a constant amplitude because there are no frictional forces and hence no energy loss.
(Total energy of oscillating system remains constant).

27
Q

Forced oscillation definition

A

oscillation due to external periodic driving force

28
Q

Time Period

A

time taken for one complete oscillation

29
Q

Frequency

A

number of oscillations per second

30
Q

Amplitude

A

maximum displacement of a particle from its rest position

31
Q

Damping definition

A

Damping is when frictional forces oppose motion, dissipating energy
(Total energy of oscillating system decreases)

32
Q

Damping descriptions

A

Light damping : takes a long time for the amplitude to decrease to zero. System oscillates at natural frequency.
Critical damping : shortest time for amplitude to decrease to zero.
Heavy damping : takes a long time for amplitude to decrease to zero. No oscillating motion occurs.

33
Q

Phase difference between driver and driven oscillations

A

Check Sheet

34
Q

Resonance curve

A

Check Sheet