M2 Dynamics

Question 1

action force

Answer 1

the force acting on a body

Question 2

balanced forces

Answer 2

when forces combine to cancel each other out

Question 3

conservation of energy

Answer 3

energy cannot be created nor destroyed, only transformed from one form to another

Question 4

conservation of momentum

Answer 4

when two or more objects interact, the total momentum is conserved if no external forces act

Question 5

contact force

Answer 5

a force acting when objects are in physical contact

Question 6

density (kg m⁻³)

Answer 6

mass of a substance per unit volume
- density = mass/volume

Question 7

dynamics

Answer 7

the study of the motion of objects and the forces acting on them

Question 8

elastic collision

Answer 8

a collision in which objects rebound with no deformation, change of shape, or production of heat. Both momentum and kinetic energy are conserved.

Σmv before = Σmv after

Σ1/2 mv² before = Σ1/2 mv² after

Question 9

energy

Answer 9

the property of a system that enables it to do work
- scalar quantity (J)

Question 10

equilibrium

Answer 10

the state of an object when not acted upon by a net force
- may be at rest or travelling at a constant velocity

Question 11

impulse

Answer 11

the change in momentum of an object
- Impulse = F x t (Ns)
- Impulse = m(v-u)

Question 12

inelastic collision

Answer 12

a collision in which momentum is conserved but kinetic energy is lost
Σmv before = Σmv after

Question 13

inertia

Answer 13

the resistance of an object to a change in its motion

Question 14

kinetic energy

Answer 14

the energy of an object due to its motion
Eₖ = 1/2 mv²

Question 15

mass

Answer 15

the amount of matter in an object (kg)

Question 16

mechanical energy

Answer 16

kinetic or potential or heat energy

Question 17

momentum

Answer 17

“mass in motion”
p = mv (Ns)

Question 18

net force

Answer 18

a single force that presents all the forces acting on a body

Question 19

Newton

Answer 19

the unit of force that will give a mass of 1kg an acceleration of 1ms⁻²

Question 20

N1L (inertia)

Answer 20

Every object continues in its state of rest or uniform motion in a straight line, unless acted on by an unbalanced force

Question 21

N2L (net force)

Answer 21

F=ma (net force)

Question 22

N3L

Answer 22

Every action force has an equal and opposite reaction force
1. the forces acting on different objects
2. same type of force
N3L force pair: force of A on B
force of B on A
3. Equal in magnitude, opposite in direction
☆ forces are equal in magnitude, but the EFFECT could be drastically different

Question 23

potential energy

Answer 23

the energy stored in an object due to its position, its shape or its state

Question 24

power

Answer 24

the rate of change of energy (Watts)
- scalar quantity

Question 25

reaction force

Answer 25

an equal and opposite force exerted by a body against a force acting upon it

Question 26

resultant force

Answer 26

the vector addition of all the forces acting

Question 27

tension

Answer 27

the force in a string connected to a mass

Question 28

terminal velocity

Answer 28

the final velocity reached by an object when the resistance force is equal and opposite to the weight force

Question 29

unbalanced forces

Answer 29

produce acceleration/deceleration

Question 30

weight

Answer 30

the force due to gravity on an object
F = mg

Question 31

work

Answer 31

energy required to make an object change its position
- scalar quantity (J)
W = net Force x displacement
W = Fs
W = ΔEₖ = 1/2 mv² - 1/2 mu² (final minus initial)

Question 32

classifying forces into

Answer 32

contact or non-contact (field)

Question 33

INCLINE PLANES

Answer 33

weight force is broken down into

force down the plane (F = mg sinθ)
force perpendicular to plane (F = mg cosθ)

FORCE PAIRS
+ down the plane & friction
+ reaction/normal force (F = mg cosθ)

Question 34

change in GPE in a uniform field (formula)

Answer 34

ΔU = mgh (also = work)

Question 35

power (formula) and more

Answer 35

P = Fv
P = W/t
W = change in energy
Power is a measure of how difficult it is to do work (If you can spread the work over a longer time, then you need to use less power)

Question 36

kinetic energy (Eₖ) formula

Answer 36

1/2 mv²

Question 37

Impulse ♡

Answer 37

Impulse is used to quantify the impact that force has on an object over a period of time
Impulse = Ft
Impulse = m(v-u) = Δp (change in momentum)

units Ns
- vector quantity

Question 38

Answer 38