Newton's First Law of Motion

Newton's first law of motion

By John Toje

Newton's First Law of Motion

What is motion?

Motion is a change in position relative to a frame of reference.

Reference Point

• A place or object used for comparison to determine if something is in motion.

• Movement is relative to an object that appears stationary

• Earth is the most common frame of reference.

Open Ended

What is the frame of reference for the sunset?

Multiple Choice

Is a person who is seated on a moving train in motion in relation to the train?

• Yes

• No

Multiple Choice

Is the same train passenger in motion in relation to a tree outside of the train?

• Yes

• No

Speed

• Speed is the distance traveled in a given amount of time.

• Speed = distance/ time

• The units for speed: meters/second (m/sec), kilometers/hour (km/hr), or miles/hour (mph).

Speed= distance/ time

Velocity

• A quantity that describes the speed of the object and its direction of travel.

• The rate of change of an object's position in a reference frame.

• Constant velocity is always motion along a straight line.

• If an object moves in a positive direction, then we use a positive number to represent the velocity.

• If an object moves in a negative direction, then we use a negative number to represent the velocity.

Multiple Choice

A place or object used for comparison to determine if another object is in motion is called a

• comparison point

• reference point

• point of view

• motion detector

Multiple Choice

A runner races in the 100 meter dash. It takes her 10 seconds to finish. What is her average speed?

• 10 m/s

• 1000 m/s

• 100 seconds

• 10 seconds

Multiple Choice

What is the formula to calculate speed?

• S = t/d

• S = d/t

• S = d x t

• S = t x d

Multiple Choice

A change in an object's position is called ______.

• Speed
• Motion
• Velocity
• Friction

Open Ended

A bus travels north along a straight stretch of road. Its velocity is a constant 15 m/s. Another bus travels south on the same road at the same speed. What is the velocity of the second bus?

Multiple Choice

The measure of how fast an object is moving and what direction it is moving

• velocity

• force

• speed

• acceleration

Multiple Choice

What is this graph showing?

• Constant Speed
• Acceleration (speeding up)
• Deceleration (slowing down)
• No motion

Newton's First Law of Motion

Unless acted on by an unbalanced force, an object at rest stays at rest and an object in motion stays in motion at a constant velocity.

Inertia and Newton's First Law

• Another name for Newton's First Law

• Inertia is the tendency of objects to resist any change in motion.

• Objects with more mass have more inertia than objects with less mass.

• More force is needed to overcome the inertia of a massive object to change its motion than is needed to cause the same change in the motion of a less massive object.

Multiple Choice

Newton’s 1st Law applies to…

• only moving objects

• only nonmoving objects

• both moving and nonmoving objects

• no objects, except those in space

Multiple Choice

If an object in motion is not acted on by an unbalanced force, it will continue with the same speed and direction.

• True

• False

Multiple Choice

An object's tendency to resist change in its state of motion.

• gravity

• force

• inertia

• friction

Multiple Choice

Which force opposes motion between two surfaces in direct contact?

• inertia

• mass

• friction

• acceleration

Multiple Choice

An object at rest will stay at rest unless an unbalanced force acts on it.

• True

• False

Multiple Choice

You push a sofa, but you can’t get it to move by yourself. Why?

• You have more inertia than the sofa.

• There is no inertia because the sofa is not moving.

• Your force is stronger than the friction between the sofa and the floor.

• The sofa’s inertia is greater than your applied force.

How to Calculate Speed

 Speed = distance divided by time

Multiple Choice

It takes Natalie 0.25 hours to drive to school. Her route is 16 km long. What is Serina’s average speed on her drive to school?

• 1 km/h

• 4 km/h

• 64 km/h

• 64 mph

Multiple Choice

A bus travels 20km in 30 minutes. What is the average speed of the bus?

• 20 km/h

• 30 km/h

• 40 km/h

• 50 km/h

Multiple Choice

Calculate the speed. Use your calculator!!!

A baseball is thrown a distance of 60 ft. in 0.5 seconds. What is the speed of the baseball?

• 120 seconds

• 120 ft./s

• 30 feet

• 30 ft./s

Multiple Choice

A baseball is thrown a distance of 60 ft. in 0.5 seconds. What is the speed of the baseball?

What value represents the distance in this problem?

• 60 ft.

• 0.5 seconds

• distance

• none of these

Multiple Choice

A baseball is thrown a distance of 60 ft. in 0.5 seconds. What is the speed of the baseball?

What mathematical operation will you perform to calculate the speed?

• add

• subtract

• multiply

• divide

Multiple Choice

A block is pulled 40 meters to the right in 10 minutes. What is the average speed the block was pulled?

• 10 meters per minute

• 4 meters per minute

• .4 meters per minute

• .10 meters per second

Fill in the Blank

A student walks 2km in 30 minutes. What is the average speed in km/h?

Pay attention to the units of measure!!!

Enter your equation and answer in the space provided.

Poll

Rate your understanding of motion and Newton's First Law.

• Level 0- Even with help, I still don't understand.

• Level 1- I'm starting to get it, but I'm still confused.

• Level 2- I can do this help, or with an example in front of me.

• Level 3- I can do this on my own. I can show I understand.

• Level 4- I am very confident with this. I can teach someone how to do this.

HAVE A GREAT DAY!!!

See you tomorrow! More calculating speed practice!