Topic 1 - Forces Part 1 (Trilogy)

Question 1

What is a scalar quantity?

Answer 1

A scalar quantity has magnitude only
- speed, mass, time, energy

Question 2

What is a vector quantity?

Answer 2

A vector quantity has magnitude and direction
- displacement, velocity, acceleration

Question 3

What is a contact force?

Answer 3

A contact force is when two objects touch each other
- friction, normal contact force, tension and air resistance

Question 4

What is a non-contact force?

Answer 4

A non-contact force does not require two objects to touch each other
- gravity, magnestism, electrostatic

Question 5

What is newtons 3rd law?

Answer 5

Every action has an equal or opposite reaction

Question 6

What is weight?

Answer 6

The gravitatinal force of attraction you experience because you are in earths gravitational field is also known as your weight

Question 7

How is weight measured?

Answer 7

Measure by using a calibrated spring balance (newton meter)

Question 8

How would we calculate the weight of an object?

Answer 8

weight = mass x gravitational field strength

w = mg

Question 9

What is the centre of mass of an object?

Answer 9

The weight of an object is the act from a single point, the object would be balances if placed on the point

Question 10

What is the resultant force?

Answer 10

If two or more forces act on an object then these can be replaced by a single force arrow we call the resultant force

Question 11

How do you calculate the size of a resultant force when two or more forces act along the same line?

Answer 11

if the forces act in the same direction we add the forces to work out the size of the resultant force

if the forces act in different direction we take the smallest one away from the biggest

Question 12

How do you calculate the size of a resultant force when two forces act at right angles?

Answer 12

Draw a scale diagram
- make a parallelogram with the two forces
- draw the reultant force and meausre it with a ruler
- to get the angle do triganometry

Question 13

What does it mean when we say we are going to resolve a force into two components?

Answer 13

Any force can be split into two componen, one acting vertically and one horizontally,can be determined by pythagorus and triganometry

Question 14

what is displacement example

Answer 14

example: running race 400m track, 400m race

first: start at the start line and finish in the same place = 0 displacement (moved nowhere)

wheras 100m race start at start finish 100m away so dispacmeent = 100

Question 15

what is displacment

Answer 15

distance in a straight line between a start and a finish point