QOD#48What does each line represent?A – B – C – D – Time

Dis

tanc

e

Acceleration (speeding up)

A

B

C

D

deceleration (slowing down)

Stopped – no motion

Constant Speed

ForcesForce – a push or pull on an object.

Unit – Newtons (N)

Types of ForcesA. ________________ - a force that is

applied when two objects touch.1. Push

ex:2. Pull

ex:

Contact forces

3. ___________________ - the resistance between two surfaces that are in contact with each other (sliding against each other).

ex:4. ___________________ - the force exerted on an object by the air as its moving. (drag

force)ex:

5. ___________________ - the upward force exerted by a fluid, which opposes the weight of an object.

ex:

Friction

Air resistance

Buoyancy

B. ____________________ - a force that one object applies to another object without touching.

1. ____________________ex:

2. ____________________ (includes static electricity)ex:

3. ____________________ex:

Non-Contact Force

Magnetic Force

Electric Force

Gravitational Force

Gravity

Buoyancy

Lift

Gravity

Thrust (push)

Drag (air resistance)

Forces WS

QOD #49Falling Feather & Golf Ball

1. What happens when we drop a golf ball and a feather down a stairwell?

2. Why does this happen?

Gravity________________ – the gravitational force exerted on an object.

Every object (that has mass) exerts a __________________________ of attraction on any other object.

Weight

gravitational force

Mass

The greater the mass of two objects, the ________________ the gravitational force is between them.

greater

Does the earth & the person or the moon & the person have a

greater gravitational force between them? Why?

DistanceThe force of gravity increases as two objects become ____________ (as the distance between the objects ______________).

The force of gravity decreases as two objects ____________________ (as the distance between the objects ______________).

closerdecreases

move farther apartincreases

Which person will feel a greater force of gravity with the

earth?

1. Between which two objects is there the greatest gravitational force (based on their mass)?a.

b.

c.

2. Between which two objects is there the greatest gravitational force (based on their distance)?a.

b.

c.

Measuring ForceForce is measured in Newtons (N)

1 Newton = lifting a stick of butter

20 Newtons = lifting a 2-L bottle of soda

Measuring Force ActivityObject Weight in Newtons (N)

QOD#50

•What is the speed of a giraffe if it travels 400 meters in 40 seconds?

Egg Drop Project

Balanced/Unbalanced ForcesForces are described in terms of ___________ and ____________ (strength).

directionmagnitude

Ex1: Pushing the box to the right

100 N

Ex2: Downward gravitational force

3 N

The ______________ is the combination of all the forces acting on an object.

net force

Ex3: Gravitational force of 15 NLift force of 15 N

Net force: __________ 0 N

Ex4:

650 N 400 N

Net force: __________ 1,050 N

Ex5:

125 N 375 N

Net force: __________ 250 N

____________________ – forces acting on any object that combine and form a net force of zero.

-When balanced forces are acting on an object, the object _________________.

Balanced forces

stays still

Ex6: 300 N 300 N

Net force: __________0 N

__________________ - forces acting on an object that combine to a net force that is not zero.

-Objects go into ___________because of unbalanced forces.

Unbalanced forces

motion

Ex7: 400 N 500 N

Net force: __________100 N

Balanced/Unbalanced WS

My Example:1. Draw a picture of a scenario with the forces and direction of

the forces labeled. 2. Another classmate is going to figure out the net force of your

made up scenario.3. Have the answer in your head. Don’t write it down in your

notebook.4. Switch notebooks with someone else, and write down the net

force in their notebook.