4a._work_energy_power (1)

What is the Law of Conservation of Energy?

Energy cannot be created or destroyed, only changed from one form to another.

What is work defined as in physics?

Work is the product of force and distance, specifically W = Fd.

What are the units for work?

The unit for work is the joule (J), equivalent to a newton-meter (N·m).

How is work done when a force is applied at an angle?

When a force is applied at an angle, work is calculated using W = Fd (cos θ).

What is kinetic energy and how is it calculated?

Kinetic energy (K) is the energy of motion, calculated as K = (1/2)mv².

What does the Work-Energy Theorem state?

A system gains or loses kinetic energy by transferring it through work.

What is potential energy?

Static energy an object possesses by virtue of its position or configuration.

How to calculate gravitational potential energy?

Gravitational potential energy is calculated as U = mgh.

What is meant by conservative forces?

Forces that do not depend on the path taken, such as gravity.

What is power defined as?

Power is the rate at which work is done, given by P = W/t.

When does negative work occur?

Negative work occurs when the force acts opposite to the direction of motion.

What is the relationship between kinetic energy and potential energy?

They have an inverse relationship; as one increases, the other decreases.

What is the total mechanical energy of a system?

The total mechanical energy is the sum of kinetic and potential energy (E = K + U).

What happens to mechanical energy in the presence of nonconservative forces?

Mechanical energy is not conserved; energy is transformed into other forms, like heat.

What is the formula for calculating power when lifting an object?

P = Fv, where F is the force and v is the velocity.

What role does work play in energy transfer?

Work transfers energy from one system to another and changes energy states.

How is the work done by a constant force calculated?

It is the area under the curve in a force versus displacement graph.

Example question: Calculate the work done lifting a mass of 2 kg a height of 1.5 m.

W = mgh = (2 kg)(10 N/kg)(1.5 m) = 30 J.

What is the formula for calculating work with friction?

W = -Ff*d, where Ff is the force of friction and d is the displacement.

When is work done zero?

Work done is zero when a force is applied perpendicular to the direction of motion.