Conservation of Energy and Calculating Energy Changes in Objects

The video explores the principle of energy conservation, focusing on gravitational potential and kinetic energy. It uses a pendulum and a vertically thrown ball to illustrate energy transfer and conservation. The video explains how energy is conserved and converted between different forms, providing equations for calculating gravitational potential and kinetic energy. Examples demonstrate how to apply these equations to real-world scenarios, emphasizing the importance of understanding energy dynamics.

What happens to the energy of a pendulum in a vacuum as it swings?

• It is lost to the surroundings.

• It is converted between gravitational potential and kinetic energy.

• It remains constant as gravitational potential energy.

• It remains constant as kinetic energy.

At what point does a pendulum have the greatest kinetic energy?

• Halfway down its swing.

• At the bottom of its swing.

• At the top of its swing.

• When it stops momentarily.

What is the relationship between gravitational potential energy and kinetic energy in a pendulum?

• They remain constant throughout the swing.

• They are constantly converted into each other.

• They are inversely proportional.

• They are always equal.

Which equation represents gravitational potential energy?

• v^2/2g

• mg/v

• mgh

• 1/2 mv^2

How is kinetic energy calculated?

• v^2/2g

• mgh

• 1/2 mv^2

• mg/v

What is the initial gravitational potential energy of a pendulum with a mass of 1.5 kg at a height of 0.2 meters?

• 1.96 Joules

• 2.94 Joules

• 4.90 Joules

• 3.92 Joules

What is the velocity of a pendulum at the bottom of its swing if its initial gravitational potential energy is 2.94 Joules?

• 3.00 m/s

• 2.50 m/s

• 1.98 m/s

• 3.50 m/s

What is the initial kinetic energy of a ball with a mass of 0.5 kg thrown at 10 m/s?

• 20 Joules

• 25 Joules

• 35 Joules

• 30 Joules

How much work is done against gravity when a ball reaches a height of 4.5 meters?

• 23.05 Joules

• 20.05 Joules

• 22.05 Joules

• 21.05 Joules

What is the work done against air resistance if the initial kinetic energy is 25 Joules and the gravitational potential energy is 22.05 Joules?

• 2.00 Joules

• 2.95 Joules

• 2.50 Joules

• 3.00 Joules