Work and Energy

Mr. Anderson explains the concepts of work and energy using the example of pole vaulting. He discusses how kinetic energy is converted into potential energy and how work is calculated using force and displacement. The video includes example problems involving a bus and a block, demonstrating the work-energy theorem and the use of force vs. displacement graphs. The importance of parallel force to displacement and the conservation of energy are emphasized.

What type of energy is primarily increased as a pole vaulter runs down the runway?

• Thermal energy

• Kinetic energy

• Elastic potential energy

• Gravitational potential energy

In a force versus displacement graph, what does the area under the curve represent?

• The total force applied

• The speed of the object

• The amount of work done

• The total displacement

How much work is done on a bus when a 12,000 Newton force moves it 48 meters?

• 620,000 joules

• 600,000 joules

• 580,000 joules

• 576,000 joules

If a bus starts from rest, what is its final velocity after work is done on it, assuming no energy loss?

• 18 m/s

• 15 m/s

• 13 m/s

• 10 m/s

When a force is applied at an angle, which trigonometric function is used to find the parallel component of the force?

• Cosine

• Cotangent

• Sine

• Tangent

What is the work done when a 30 Newton force is applied over 4 meters?

• 135 joules

• 128 joules

• 120 joules

• 140 joules

How do you calculate the work done when the force decreases linearly to zero over a distance?

• Multiply the initial force by the distance

• Use the average force over the distance

• Calculate the area of a triangle under the force-displacement graph

• Use the final force value only