# Mechanics

• Created by: Jawike
• Created on: 13-05-18 13:20
you are given: s, u, t, a what equation do you use?
s = ut + 1/2at^2
1 of 19
you are given: v, u, a, s what equation do you use?
v^2 = u^2 + 2as
2 of 19
you are given: v, u, a, t what equation do you use?
v = u +at
3 of 19
you are given: s, u, v, t what equation do you use?
s = 1/2(v+u)t
4 of 19
Newtons 1st law
a body will remain in the same state of motion unless acted upon by an unblalanced force.
5 of 19
Newtons 2ndlaw
Σf = ma
6 of 19
Newtons 3rd law
(forces act in pairs) if body A exerts a force on body B, body B will exert force equal in magnitude but opposite in direction to A
7 of 19
w = mg
(weight = mass x gravity) can be used whenever we are resolving a vertical force on earth
8 of 19
pulleys
2 (Σf=ma equations), where acceleration must be opposite, tension is the force opposite to friction/gravity, and can be found using Σf=ma
9 of 19
vectors, method 1 (tip and tail)
join the forces end to end, works best if forces are at right angels, use Trig to find angles, and pythagorus to fing magnitude
10 of 19
vectors, method 2 (cosine rule)
add the forces end to end, and use the cosine rule to find the angle and magnitude from the object
11 of 19
vectors, method 3 (co-plannar)
break up the forces into their horisontal and vertical componants, take the sum of the vertical and horisontal componants, and use trig and pythagorus to find the resultant force
12 of 19
Ek = 1/2mv^2
kinetic energy = 1/2 mass x velocity^2
13 of 19
displacement time graphs
gradient: velocity area beneath curve: N/A
14 of 19
velocity time graphs
gradient: acceleration area beneath curve: displacement
15 of 19
acceleration time graphs
gradient: N/A area beneath curve: velocity
16 of 19
force body diagrams
a dot, in the middle represents the object it act's as as a particle (it has no volume), the forcesare shown as arrows with e their respective direction, and mtheir magnitude is displayed by the length of the arrow
17 of 19
terminal velocity
this is the fastest an object due to resistive forces, e.g drag/ friction
18 of 19
P= mv
momentum = mass x velocity in a contained collision( no external force) momentum is always conserved P(before)=P(after)
19 of 19

## Other cards in this set

### Card 2

#### Front

you are given: v, u, a, s what equation do you use?

v^2 = u^2 + 2as

### Card 3

#### Front

you are given: v, u, a, t what equation do you use?

### Card 4

#### Front

you are given: s, u, v, t what equation do you use?

Newtons 1st law