(5) Forces and their Interactions

Question 1

What is a scalar quantity?

Answer 1

A quantity that only has magnitude (meaning size), it isn’t direction dependant

For example: temperature or time

Question 2

What is a vector quantity?

Answer 2

A quantity that has magnitude and an associated direction.
They are represented by an arrow, the length is the magnitude and the direction of the arrow is the direction of the vector.

For example: force or velocity

Question 3

Define a force:

Answer 3

A push or pull that acts on an object due to the interaction with another object. It’s a vector quantity

Question 4

What is a contact force and three examples?

Answer 4

A contact force is when the objects are physically touching.
1) Friction
2) Air resistance
3) Tension

Question 5

What is a non contact force and three examples?

Answer 5

A non contact force is when the objects are physically separated.
1) Gravity
2) Electrostatic force
3) magnetic force

Question 6

What is weight? Equation?

Answer 6

A force that acts on an object due to gravity and the objects mass

Weight = mass x gravitational field strength

Question 7

What quantities does weight depend on?

Answer 7

• the objects mass
• the gravitational field strength at the given position in the field

Weight and mass are directly proportional to the

Question 8

What are the units of weight and gravitational field strength?

Answer 8

Weight - newton (N)
Gravitational field strength- N/kg

Question 9

What is meant by the objects centre of mass?

Answer 9

A single point where an object’s weight can be considered to act through. Where it’s mass is concentrated

Question 10

What equipment is used to measure an object’s weight?

Answer 10

Calibrated spring balance (newtonmeter)

Question 11

What is the resultant force?

Answer 11

A single force that has the same effect as all the forces acting on the object.