Forces and Elasticity

Question 1

Magnitude

Answer 1

Any number with units

Question 2

Scalar

Answer 2

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

Question 3

Vector

Answer 3

Any quantity in physics that has both magnitude and direction

Question 4

Scalar examples

Answer 4

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

Question 5

Vector examples

Answer 5

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

Question 6

Vector addition

Answer 6

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

Question 7

Newtons 1st rule

Answer 7

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.

Question 8

Newtons 2nd rule

Answer 8

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

Question 9

Acceleration(m/s*2)=

Answer 9

Mass (kg)

Question 10

Newtons 3rd rule

Answer 10

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

Question 11

Force(f)=

Answer 11

mass(m) x acceleration(a)

Question 12

Forces acting on moving objects

Answer 12

Thrust
Reaction 
Gravity 
Air resistance 
Friction

Question 13

When something accelerates what forces act on it most

Answer 13

Most: Thrust, Air resistance, Friction

Least: Reaction, Gravity

Question 14

When something decelerates what forces act on it most

Answer 14

Most: Friction

Least: Air resistance, Thrust, Gravity, Reaction

Question 15

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

Answer 15

Most: Thrust, Air resistance

Least: Reaction, Gravity, Friction

Question 16

Centre of mass

Answer 16

The single point an object that weighs, acts on

Question 17

How to test centre of mass

Answer 17

Use a plumbline

Question 18

Centre of mass rule

Answer 18

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.

Question 19

What is mass

Answer 19

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

Question 20

What is acceleration

Answer 20

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

Question 21

What is force

Answer 21

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)

Question 22

How to calculate the deceleration of a vehicle?

Answer 22

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

Question 23

F(force in newtons,N)=

Answer 23

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

Question 24

What is extension of a spring is directly proportional to?

Answer 24

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

Question 25

Extension =

Answer 25

Length at the stage - original length