Unit 4 Physics II Day 5: Balanced and Unbalanced Forces

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Physics II Day 5: Balanced and Unbalanced Forces

BALANCED FORCES:

The net force being exerted on this book is 0. The force is balance and the book is said to be in equilibrium.

UNBALANCED FORCES:

The net force being exerted on the ground is 20 Newtons. The force is

 Unbalanced because it is not equal

 and the person will move in the direction of the greater force.

Unbalanced forces cause motion!

To analyze a diagram of a balanced or unbalanced force…

1)    Decide if the forces are balanced or unbalanced. If the forces are _balanced, they will often be represented with equal sized arrows.

2)    The forces are only balanced if they are equal and in opposite directions. If the forces are unbalanced, the greater force is usually represented by a larger or longer arrow.

3)    The object will usually move in the direction of the greater  arrow!

Let’s Try as a Class:

1) In a fight over a teddy bear, Fatima pulls with 45 newtons of force and Miguel pulls with 33 newtons of force. This diagram represents their tug-of-war.

 Are the forces balanced or unbalanced?

Which way will they move?

a)     Maria will move towards Omar

b)    Omar will move towards Maria

c)     They will not move

d)    Omar and Maria will move in opposite directions

What is the net force in that direction? ________________ newtons

Check Yo' Self

 

Lifework

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1) In a rocket, the upward moving thrust is a force of 3,000 newtons. The downward force of gravity on the rocket is 2,000 newtons. Draw the diagram.

Are the forces balanced or unbalanced?

In which direction will the rocket move?

What is the net force on the rocket in that direction?

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2) In a tug of war, Malaysia pulls to the left with 50 newtons of force. Damian pulls to the right with 50 newtons of force.  Draw the diagram.

Are the forces balanced or unbalanced?

Which way will they move?

a)     They will move left.

b)    They will move right.

c)     They will not move.

d)    They will move towards each other.

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3) A baseball is flying towards Oliver with 542 newtons of force. He pushes back against it with a bat with a force of 1,000 newtons. Draw the diagram.

Are the forces balanced or unbalanced?

Which way will the ball move?

What is the net force on the ball in that direction?

4) Jacob is pushing forward on a door with a force of 88 newtons. Nadia is also pulling in the same direction with a force of 50 newtons. Draw the diagram.

Are the forces balanced or unbalanced?

Will the door move forwards or backwards??

What is the net force exerted on the door?

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6) Anthony is walking his chicken. He pulls with a force of 20 N while the chicken pulls back with a force of 10N. Draw the diagram.

Are the forces balanced or unbalanced?

What do you predict will happen?

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7) Jaylen is walking his pet hamster. The hamster pulls forward with a force of 8 newtons. Jaylen  pulls back with a force of 22 newtons. Draw a diagram that represents these forces.