define a force. what unit are forces measured in? how can we measure a force?

Balanced and unbalanced forces

Define a force.

What unit are forces measured in?

How can we measure a force?

Balanced and unbalanced forces

Objectives

Know what balanced and unbalanced forces are.

Understand the effect if forces are balanced and

unbalanced.

Outcomes

(4) Draw diagrams to represent balanced and unbalanced

forces.

(5) Calculate resultant forces.

(6) Explain the effects of balanced and unbalanced forces

on objects.

Key terms: Force, Newton, balanced, unbalanced, resultant.

Balanced Forces produce

NO change in Movement

Unbalanced Forces

Change the Speed and or

Direction of Moving Objects

Balanced and Unbalanced Forces

The forces on the person are balanced

The floor pushes upward on the person

Weight pulls downwards on the person

Greater Force

Smaller Force

DA B CResistance

Weight

Weight

Resistance

Weight

Which diagram is correct?

Why?

Resistance

THRUSTDRAG & FRICTION

What is the bicycle doing?

C

A

B

D

Not moving

Slowing down

Speeding up

Moving at constant speed

If the swimmer is floating, which diagram is correct?

WEIGHT WEIGHT WEIGHT WEIGHT

TURBULENCEDRAGUPTHRUSTRESISTANCE

BA E D

WEIGHT

DRAG

B

A

C

D

Hovering in the air

Falling at constant speed

Slowing down

Speeding up (plunging to a horrible death)

What is the parachutist doing?

Which diagram shows a balloon floating at a constant height?

WEIGHT

UPTHRUST

WEIGHT

UPTHRUST

WEIGHT

UPTHRUST

WEIGHT

DRAG

DA B C

THRUST THRUST

THRUST THRUST

DRAG & FRICTION

DRAG & FRICTION

DRAG & FRICTION

DRAG & FRICTION

Which car is slowing down?

C

A B

D

TITANIC

WHITE STAR LINE

Which statement is not correct?

The Titanic is sinking because the upthrust on it is less than its weight

The iceberg is floating because the upthrust on it is equal to its weight

The Titanic is sinking because there is less upthrust on it than there is on the iceberg

The Titanic weighs less than the iceberg

B

A

C

D

WEIGHT

WEIGHT

UPTHRUST

UPTHRUST

Copy the diagrams below, adding arrows to show ALL the forces acting on the object indicated

A stone in a beaker of water

An ice skater moving at constant speed

A plane accelerating forwards in the air

WEIGHT

RESISTANCE

UPTHRUST

WEIGHT

RESISTANCE

THRUSTFRICTION & DRAG

DRAG THRUST

WEIGHT

LIFT

Balanced and unbalanced forces

Task

Answer the questions on the worksheet.

Outcomes

(4) Draw diagrams to represent balanced and unbalanced

forces.

(5) Calculate resultant forces.

(6) Explain the effects of balanced and unbalanced forces

on objects.

Key terms: Force, Newton, balanced, unbalanced, resultant.

Balanced and unbalanced forces

Peer review

Exchange sheets.

Mark the other persons sheet, give them a total

mark.

Clearly write who has marked the work.

Outcomes

(4) Draw diagrams to represent balanced and unbalanced

forces.

(5) Calculate resultant forces.

(6) Explain the effects of balanced and unbalanced forces

on objects.

Key terms: Force, Newton, balanced, unbalanced, resultant.

In which direction will these stationary objects move?

Will it move?

ForceNewton Newton

MeterFriction

Density

Balanced

Unbalanced

GravityWeight

Mass

Kilogram

Speed Metres persecond

Volume

Upthrust