Kin 216: Free Body Diagrams

What is a free body diagram

Allows you to visualize force. 
Allows you to visualize the direction and magnitude of applied forces and the resulting reaction on a body

is an FBD a scaled drawing

No, it’s a problem-solving strategy

Signs for adding forces

Positive = up, right

Negative = down, left

In what cases can forces be summed together?

If forces are acting in parallel and in same direction, you can compose them into one vector by summing the two forces

When forces are acting in horizontal and vertical planes, how can they be summed together?

Forces acting on different planes can be summed together using “Vector Addition”

A vector can be broken down into?

It’s horizontal (x) and vertical (y) components

What can we use to calculate the magnitude of a vector?

We can use the x and y components and Pythagorean theorem to calculate the magnitude of a vector

Instead of pythagorean theorem, what else can be used to calculate the magnitude of a vector

If we know the angle, we can use trigonometric fx to solve for the x and y components and the magnitude of a vector

Is it easier to push or pull a desk across the room?

It’s easier to pull a desk across the room
When you push → Reaction Force = Wt of desk + F

When you pull → Reaction force = Wt of desk - F

Pulling the desk allows you to reduce the reaction force by reducing the friction

Between and end of lecture math questions

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A projectile motion lecture math questions

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