Work Energy Theorem Example Problem

The video tutorial covers a physics problem involving a 5.0 kg mass and its change in velocity. The teacher guides students through solving the problem using the work-energy theorem, explaining why other work equations are not applicable. The process includes calculating the net work done on the mass by considering the change in kinetic energy. The tutorial emphasizes the importance of understanding vector operations and careful handling of negative values in calculations.

What is the initial velocity of the object in the problem statement?

• 3.0i - 4.0j m/s

• 5.0i + 3.0j m/s

• 4.0i - 3.0j m/s

• 2.0i + 6.0j m/s

Which theorem is chosen to solve the problem instead of the standard work equations?

• Work-Energy Theorem

• Hooke's Law

• Conservation of Momentum

• Newton's Second Law

What does the work-energy theorem relate to in this problem?

• Change in potential energy

• Change in kinetic energy

• Change in thermal energy

• Change in gravitational energy

How do you square a unit vector expression like 2i + 6j?

• Use the cross product

• Add the components

• Use the dot product

• Multiply each component by 2

What was the error in the initial calculation of net work?

• Wrong formula used

• Incorrect mass value

• Sign error in velocity components

• Forgetting to square the velocity components

What is the final calculated net work done on the object?

• 38 Joules

• 45 Joules

• 50 Joules

• 82 Joules

Why is it important to memorize the work-energy theorem?

• It is frequently used in chemistry

• It is not on the AP Physics equation sheet

• It is the only way to solve all physics problems

• It is a fundamental concept in biology