lesson #11

Lesson #11
E.Q:How do Free Body Diagrams help us analyze forces and predict an object's motion in real-world scenarios?

• Lesson Objectives:

  • Students will understand what a Free Body Diagram (FBD) is.

  • Students will be able to draw FBDs for different physical situations.

  • Students will be able to apply the concept of FBDs to solve force and motion problems.

Multiple Choice

What do the arrows or vectors represent?

• forces acting on the object

• all the acceleration acting on the object

• all the ways an object can move

Multiple Choice

Is force a vector?

• yes

• no

Board demonstration

Multiple Choice

A skier has reached the bottom of a hill and is coasting to the right while slowing down along the loosely-packed snow. Ignore air resistance.

What is the direction of the FRICTION force?

• There's no friction force

Multiple Choice

A skier has reached the bottom of a hill and is coasting to the right while slowing down along the loosely-packed snow. Ignore air resistance.

What is the direction of the NORMAL force?

• There's no normal force

Multiple Choice

A downward-moving skydiver who has just opened the parachute is slowing down.

Ignore air resistance.

What is the direction of the TENSION force?

• There's no tension force

Multiple Choice

A rightward force is applied to a dresser to accelerate it to the right across the bedroom floor. Ignore air resistance.

What is the direction of the APPLIED force?

• There's no applied force

Multiple Select

A hockey puck glides to the right across the ice at a constant speed. Ignore air resistance.

Which forces are the same?

• Normal force

• Friction force

• Gravity force

• Applied force

Multiple Choice

Name the missing force....

• weight force
• normal force
• frictional force
• tension force

Multiple Choice

Name the missing force...

• frictional force
• weight force
• thrust
• buoyant force

Multiple Choice

What is the NET FORCE of this diagram?

• 17 N, right

• 17 N, leftvvv

• 23 N, right

• 12 N, up

Multiple Choice

What forces are on a leopard laying on a log?

• F_g & F_app

• F_b & F_g

• F_g & F_N

• F_f & F_N

HOMEWORK

• Problem 1: A 5 kg object is at rest on a table. Draw the FBD.

• Problem 2: A 3 kg object is being pushed to the right with a force of 10 N on a frictionless horizontal surface. Draw the FBD and find the acceleration of the object.

• Problem 3: A 2 kg object slides down an inclined ramp 30° with the horizontal, with friction being 10% of the normal force. Draw the FBD, find the friction force and the acceleration of the object.