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Flashcards in Forces and Elasticity Deck (25)
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1
Q

Magnitude

A

Any number with units

2
Q

Scalar

A

Any quantity in physics that has a magnitude, but not a direction associated with it.

3
Q

Vector

A

Any quantity in physics that has both magnitude and direction

4
Q

Scalar examples

A

Pressure, density, potential difference, power, temperature, wavelength, frequency

5
Q

Vector examples

A

Velocity, acceleration, force, momentum, magnetic field, displacement, current

6
Q

Vector addition

A

If two similar vectors point in the same direction, add them

7
Q

Newtons 1st rule

A

Every object remains in its state of rest or continuous at a constant speed in a straight line unless an overall/resultant force acts upon it.

8
Q

Newtons 2nd rule

A

Unbalanced forces cause acceleration… The magnitude of the acceleration, a, depends on:

i) the size of the unbalanced force, F
ii) the mass of the object

9
Q

Acceleration(m/s*2)=

A

Mass (kg)

10
Q

Newtons 3rd rule

A

For each force there is another force acting in the opposite direction with the same strength

11
Q

Force(f)=

A

mass(m) x acceleration(a)

12
Q

Forces acting on moving objects

A
Thrust
Reaction 
Gravity 
Air resistance 
Friction
13
Q

When something accelerates what forces act on it most

A

Most: Thrust, Air resistance, Friction

Least: Reaction, Gravity

14
Q

When something decelerates what forces act on it most

A

Most: Friction

Least: Air resistance, Thrust, Gravity, Reaction

15
Q

When something is at a steady speed what forces act on it most

A

Most: Thrust, Air resistance

Least: Reaction, Gravity, Friction

16
Q

Centre of mass

A

The single point an object that weighs, acts on

17
Q

How to test centre of mass

A

Use a plumbline

18
Q

Centre of mass rule

A

If the line of action from the centre of mass is inside the width of the base it will not topple. But if it goes outside it will then topple.

19
Q

What is mass

A

Mass refers to the amount of a substance - the amount of matter in a substance/object. Measured in kilograms (kg)

20
Q

What is acceleration

A

Refers to an objects change in velocity (either getting faster or slower). Measured in m/s*2

21
Q

What is force

A

Is a push or pull on a object. Can change the velocity of something, the direction it is moving in or its shape (stretch or squash)

22
Q

How to calculate the deceleration of a vehicle?

A

v^2=u^2+2as
s=distance travelled
u=initial speed
v=final speed

23
Q

F(force in newtons,N)=

A

K x e
K=the spring constant in newtons per metre N/m
e=extension in metres, m

24
Q

What is extension of a spring is directly proportional to?

A

The force applied, as long as its limit of proportionality is not exceeded (HOOKE’S LAW)

25
Q

Extension =

A

Length at the stage - original length