Exploring Internal and External Forces

The video tutorial explores forces acting on systems, focusing on internal and external forces, and how to define a system. It explains the use of free body diagrams and applies Newton's Third Law to systems. The tutorial includes example calculations to demonstrate how to determine forces and acceleration in systems of multiple objects.

What is the purpose of defining a system and creating a boundary around it?

• To ignore all forces

• To simplify calculations by removing all forces

• To determine external forces acting on the system

• To identify internal forces only

When considering forces in a system, what is typically treated as a system?

• A single molecule

• A single atom

• Larger objects like boxes or trains

• Only the ground

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What happens when you push on one of two touching boxes?

• Only the first box moves

• The second box moves independently

• Both boxes remain stationary

• The first box pushes the second box

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In a free body diagram, what does the force of box B on box A represent?

• An external force

• An internal force

• A gravitational force

• A frictional force

What is the result of combining the free body diagrams of two boxes?

• The external forces increase

• The weight force becomes zero

• The internal forces cancel each other out

• The normal force decreases

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What is the net force acting on a system of two boxes if the only external force is the force of the hand?

• The normal force

• The force of the hand

• The weight of the boxes

• The sum of the internal forces

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How do you calculate the acceleration of a system of two boxes being pushed by a hand?

• By multiplying the force of the hand by the total mass of both boxes

• By dividing the force of the hand by the mass of one box

• By multiplying the force of the hand by the mass of one box

• By dividing the force of the hand by the total mass of both boxes

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If each box weighs 10 kg and the system is accelerated at 1 m/s², what is the force of the hand?

• 30 Newtons

• 20 Newtons

• 10 Newtons

• 40 Newtons

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What is the force of box B on box A if the force of the hand is 20 Newtons and each box is 10 kg?

• 20 Newtons

• 5 Newtons

• 15 Newtons

• 10 Newtons

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Why do we often treat a system of multiple objects as a single object?

• To increase the net force

• To simplify calculations

• To ignore internal forces

• To decrease the mass

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