newtons laws and forces

What is speed?

The distance the object travels in a certain amount of time

What is the formula for speed?

Speed = distance/time

What is velocity? And how is it different from speed

Velocity is the speed and direction of an object in motion. It is different from speed because speed is scalar and doesn’t include the direction of an object.

Is velocity a vector? And what does a Vector show?

yes, a vector shows speed and direction (magnitude/ speed)

What is acceleration?

Acceleration is the rate of change of velocity

What are three ways acceleration change?

By increase in speed, decrease in speed, or change in direction

how do you calculate average acceleration?

Final velocity - starting velocity/ time (final time - starting time)

What is force?

Force is a push or pull motion and all has 2 properties. (Direction and size; shown using vector arrows)

Relate force and motion

Force can cause a stationary object to move or can cause a moving object in motion to change direction, speed, or both

What is a balanced force?

A balanced force is where 1) both forces are equal in size and are always acting in opposite directions on an object. 2) net force is always 0. 3) Object stays in same direction, speed, or stays still

What is an unbalanced force?

1) the 2 forces aren’t equal in size and in opposite direction. 2) Moving object continues moving when removed. 3) causes change in motion such as, position, direction and speed.

F2=18N___ F1=20N is this balanced or unbalanced?

Unbalanced

Define friction and why it occurs

Friction is a force that opposes between two surfaces that touch.

It occurs when any object is rough or because of hills and valleys which causes friction even through smooth objects through contact.

Give an example of sliding friction

Sledding

2 ways to reduce sliding friction

Polishing surfaces and lubrication

Give an example of rolling friction.

Anything with wheels

An example of static friction

A still object like a heavy boulder or car that is in rest

Fluid friction (example)

Airplane or swimming

2 ways friction can be harmful

Causes wear and tear and can generate heat

2 ways friction can be helpful.

Reduces motion and cap help stop a car (breaks)

What does Newton’s First Law of Motion state?

An object at rest stays at rest until an unbalanced force acts on it.

An object in motion will stay in motion at a constant VELOCITY unless acted on by an unbalanced force.

What can an unbalanced force do in regards to motion?

An unbalanced force could cause change in velocity in regards to motion.

What is inertia

An objects resistance to an unbalanced force

how does mass relate to inertia?

The more mass and the more inertia.

What does Newton’s Second Law of Motion state?

The acceleration of an object

depends on the mass of the

object and the amount of Force applied

What is the relationship between force and acceleration

More force more acceleration

A car with a mass of 1000 kg accelerates when the traffic

light turns green. If the net force on the car is 4000 N, what’s

the car’s acceleration?

a=F/m. (INCLUDE direction)

a= 4m/s² forward

What is the relationship between mass and acceleration?

The more mass = the more force needed to keep the object in acceleration or to accelerate the object.

F= m•a

What does Newton’s Third Law of Motion state?

For every action there is an equal and opposite reaction. Meaning if one object exerts a force to a second object that second object will exert back a force that is both equal and opposite of the first force

What is action force?

What happens first.

What is reaction force?

What happens next

A 12 kg cart is being pushed across a rough floor with a force of 50 N. The friction force acting against the motion is 18 N.

1) What is the net force acting on the cart?

2) what is the acceleration of the cart?

3) The cart starts from rest, what will its velocity be after 4 seconds?

Net force= push force - friction force

Net force=32N

2.7 m/s² forward

10. 7 m/s² forward