An electrical kettle uses 60J of energy to heat water when supplied with 80J of electrical energy. Calculate the efficience of the kettle

The force needed to overcome static friction is usually less than that needed to overcome kinetic friction.true or false?

Which of the following best describes internal energy? a. the difference between the kinetic and potential energies of the particles in a system b. the sum of the kinetic and potential energies of the particles in a system c. the sum of the kinetic and thermal energies of the particles in a system d. the difference between the kinetic and thermal energies of the particles in a system

Language is not the only way that humans communicate. describe how we use sound, touch, chemicals, and sight to communicate. need answer asap