How much heat energy (in megajoules) is needed to convert 7 kilograms of ice at - 9 degrees Celsius to water at 0 degrees Celsius?

A) 3.09 MJ

B) 2.13 MJ

C) 2.48 MJ

D) 3.26 MJ

Although the production of heat may be bad in some cases, describe another example where the production of heat is good.

The spring of a toy car stores 10 J of potential energy. Only 8 J of energy changes to kinetic energy as the car moves. What happens to the remaining 2 J of energy?

A women in an elevator lets go of her briefcase but it does not fall to floor. How is the elevator moving

A sound technician is testing the sound acoustics in a theatre for an upcoming music concert. As he moves towards the speakers, he notices the pitch of the music gets higher.

How can baking soda extinguish fires?

Potential energy and kinetic energy are created when work is done to change a position (PE) or a state of motion (KE). Ignoring friction, how does the amount of work done to make the change compare to the amount of PE or KE created? a.

The wavelength of a wave is the wavelength of a wave is how strong the wave is. equal to the speed of the wave times the wave's frequency. the distance between where the wave is emitted and where it is absorbed.

What is a carbon whip?

2 A scientific theory is

Explain the roles of Earth's own energy sources and solar energy in the rock cycle