Work and Power Concepts

The video tutorial covers topics for an upcoming quiz, focusing on work and power calculations. It explains how to calculate work using force and distance, and how to determine power as work over time. The work-kinetic energy theorem is introduced, and several example problems are solved to illustrate these concepts. A discussion on the work done by friction is included, followed by a detailed problem involving an ice skater's speed change. The video concludes with study tips and advice for quiz preparation.

What is the formula for calculating work when there is an angle between force and displacement?

• Work = Force x Distance

• Work = Force x Distance x sin(theta)

• Work = Force x Distance x cos(theta)

• Work = Force x Distance x tan(theta)

If a force and displacement are in opposite directions, what is the sign of the work done?

• Positive

• Negative

• Zero

• Undefined

How is power calculated in terms of work and time?

• Power = Work / Time

• Power = Work + Time

• Power = Time / Work

• Power = Work x Time

What is the unit of power?

• Watts

• Newtons

• Joules

• Meters

In the example of students lifting boxes, which student developed more power?

• Neither developed any power

• Student B

• Student A

• Both developed the same power

What is the work done by friction if a box is pulled at constant speed across a rough floor?

• Negative

• Depends on the speed

• Positive

• Zero

What theorem relates work to the change in kinetic energy?

• Hooke's Law

• Conservation of Energy

• Work-Kinetic Energy Theorem

• Newton's First Law

How much work is required to increase the speed of a 50 kg ice skater from 4 m/s to 9.4 m/s?

• 1000 Joules

• 400 Joules

• 1809 Joules

• 2209 Joules

What happens to the work done when an object is brought to rest?

• It becomes zero

• It remains the same

• It becomes positive

• It becomes negative

Why is it important to keep units in calculations?

• To make calculations easier

• To confuse the examiner

• To avoid losing points on exams

• To increase the number of steps