unit 15 lesson 1 what are forces? · 3/15/2018 · lesson 1 what are forces? ... the oars, causing...

Unit 15 LESSON 1 WHAT ARE FORCES?

Unit 15 Lesson 1 What Are Forces?

Copyright © Houghton Mifflin Harcourt Publishing Company


Pushing and Pulling


• A force is a push or pull.

• Forces can cause an

object at rest to move, speed up, slow down, change direction, or stop.

• Forces can change the

shape of an object.

../../G6 1st semester lessons/Unit 15-lesson 1/15.1 images/Force.PNG

15.1 videos/Force Work and Energy Relationship - Videos for Kids by www.makemegenius_com.mp4


Pushing and Pulling


• For example, when rowers pull back on oars, the oars push against the water. The water pushes back against the oars, causing the boat to move.

• The larger the force, the greater the change it can cause to the motion of an object. Smaller forces cause smaller changes.


Pushing and Pulling



Pushing and Pulling


• Spring scales are used to measure force in units called Newton (N).


Pushing and Pulling


Two Common Forces


Gravity

• Gravity is a force of attraction toward the center of Earth. It acts even when objects are not touching.


../../G6 1st semester lessons/Unit 15-lesson 1/15.1 images/gravity.PNG

15.1 videos/Gravity, Force, and Work (clip).mp4

Two Common Forces


Gravity


Two Common Forces


Gravity

• The size of the force

increases as the mass of the objects increases.


Two Common Forces


Gravity


Two Common Forces


Gravity

• The size of the force

decreases as the distance between the objects increases.


Friction

• Friction is a force that opposes motion and acts between two objects that are touching.

• Friction can also exist between

air and a moving object. This is called air resistance.

• Friction can also change the energy of motion into thermal energy.



../../G6 1st semester lessons/Unit 15-lesson 1/15.1 images/friction.PNG

15.1 videos/What is Friction_ _ Mocomi Kids.mp4

Friction




Balanced or Unbalanced?


• Balanced forces are forces on an object that are equal in size and opposite in direction.

• Unbalanced forces are

forces that cause a change in motion.

• A force must overcome the

force of friction before an object will move.

../../G6 1st semester lessons/Unit 15-lesson 1/15.1 images/balanced forces.PNG

../../G6 1st semester lessons/Unit 15-lesson 1/15.1 images/balanced forces.PNG

../../G6 1st semester lessons/Unit 15-lesson 1/15.1 images/unbalanced forces.PNG

../../G6 1st semester lessons/Unit 15-lesson 1/15.1 images/unbalanced forces.PNG

15.1 videos/Balanced and Unbalanced Forces _ Forces and Motion _ The Fuse School.mp4


Balanced or Unbalanced?



Pull (or Push) Harder!


15.1 videos/Calculating Speed _ Forces and Motion _ The Fuse School.mp4




• A large force will cause a large change in the motion of an object. A small force will cause little change.

• The large force makes the object change its velocity, or accelerate, quickly.

• Changes in velocity include changes in

speed and changes in direction.

15.1 videos/Newton's 3 (three) Laws of Motion - trimmed.mp4


I’m Not Moving!


• The larger the force applied to an object, the greater the acceleration.




• What should the boy do differently to make the bell ring?


I’m Not Moving!


• When the same force is applied, objects with greater mass accelerate more slowly than objects with less mass.


I’m Not Moving!


• The less an object’s

mass is, the less force is needed to change its motion.


I’m Not Moving!



I’m Not Moving!


• Why does it take the full truck longer to stop than the empty truck?


Let’s Go to Mars!


• An understanding of forces helped to safely send a spacecraft to Mars.

15.1 videos/How do Rockets Work_ Basic Principle _ Mocomi Kids.mp4


Let’s Go to Mars!


• Balanced forces allowed a

spacecraft to move in one direction at a constant velocity through space.

• Once the spacecraft reached

Mars, it accelerated toward the surface because of gravity.

15.1 videos/How to Get to Mars. Very Cool! HD.mp4


Let’s Go to Mars!


unit 15 lesson 1 what are forces? · 3/15/2018 · lesson 1 what are forces? ... the oars, causing...

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