4 Work and power Flashcards
What is energy?
Energy is the ability to do work.
What is the formula for work done?
Work done = force x distance
What are the units involved in the work done formula?
(J) = (N) x (m)
What is work done equal to?
The amount of energy transferred.
What is the formula for gravitational potential energy?
GPE = mass x gravitational field strength x height
What is the formula used to find kinetic energy?
KE = 1/2 x m x s^2
What is the link between gravitational potential energy, kinetic energy and work.
On a roller coaster the highest point has high gravitational potential energy, but low kinetic energy.
On a roller coaster the lowest point has low kinetic energy, and high gravitational potential energy.
How do you do a question which concerns gravitational potential energy but it doesn’t have force and it has mass?
You find out the force by using the formula f = m x a.
Then you’ve found the force.
What is power?
Power is the rate of transfer of energy or the rate of doing work.
What is the formula for power?
Power = work done / time taken
How does heat turn into kinetic energy?
When a substance absorbs heat energy, its temperature increases. As the temperature rises, the kinetic energy of the particles within the substance also increases. This leads to an increase in the overall motion of the particles, resulting in an increase in the substance’s kinetic energy. For example, when a gas is heated, its molecules move faster, thereby increasing their kinetic energy.
How does heat turn into gravitational potential energy?
Heat energy can be indirectly converted to gravitational potential energy through the process of phase change. When a substance undergoes a phase change, such as from a liquid to a gas, it absorbs heat energy. This energy is used to break the intermolecular forces holding the particles together, allowing them to separate and transition to a higher energy state. This change in state can result in an increase in the substance’s height, leading to a gain in gravitational potential energy. For instance, when water evaporates and rises as vapour, it gains gravitational potential energy due to its increased elevation.
