Resultant Forces

Question 1

What is force

Answer 1

A push or pulls that acts on an object due to the interaction with another object

Question 2

Is force scalar or vector

Answer 2

Vector, have both magnitude (size) and direction

Question 3

What is resultant force

Answer 3

A single force that has the same effect as all of the original forces acting together
(Subtract the smaller force from the larger)

Question 4

Scalar and vector quantities

Answer 4

Scalar- only has size (magnitude)
Vector- has size and direction

Scalar:
- distance
- time
- speed
- mass
- temperature
- energy

Vector:
- force
- weight
- velocity
- acceleration
- momentum
- displacement (distance in a certain direction)

Question 5

What are forces measured in

Answer 5

Newtons (N)

Question 6

Contact forces

Answer 6

• 2 objects physically touching during interaction
• tension
• friction
• air resistance
• normal contact force (2 objects in direct contact applying a force on each other)

Question 7

Non contact forces

Answer 7

• 2 objects that are physically separate during interaction
• gravitational force
• electrostatic force
• magnetic force

Question 8

What is mass

Answer 8

• how much matter is in an object
  Kilogram (Kg)
• mass stays the same everywhere

Question 9

What is weight

Answer 9

• the force acting on an object due to gravity
  Newton (N)
• the weight of an object does depend on where it is
  Weight = mass x gravitational field strength

Question 10

What is gravitational field strength

Answer 10

• the measure of the force of gravity in a particular location
• for the Earth, 9.8 g

Question 11

What is gravitational force measured in

Answer 11

N/kg

Question 12

What links weight and mass

Answer 12

They are directly proportional to each other

Question 13

What is centre of mass

Answer 13

• the weight of an object can be considered to act at a single point
• this point is the centre of mass

Question 14

What makes an object elastic

Answer 14

If it returns to its original shape when the forces deforming it are removed

Question 15

The increase in length of a stretched material from its original length is called extension
What is the equation

Answer 15

Extension = stretched length - original length

Question 16

Stretch test required practical

Answer 16

• hang the elastic material from a clamp
• measure it’s original length with a ruler
• hang an empty
• hang a weight from the elastic material and keep increasing it
• the length of the material is measured each time a weight is added
• the total weight added and the total length of the strip are recorded in a table

Question 17

What is hooke’s law

Answer 17

• the extension of a spring is directly proportional to the force applied, as long as it’s limit of proportionality is not exceeded

Force applied (N) = spring constant (N/m) x extension (metres)
- the stiffer the spring, the greater the spring constant