4.1.1 Energy Changes in a System

Question 1

What happens to energy in a closed system?

Answer 1

It can neither enter or leave. The net change in the total energy of a closed system is always zero.

Question 2

Where does energy go when a system changes?

Answer 2

It is transferred between different objects in the system or between different types of energy stores.

Question 3

What is another way of saying work done?

Answer 3

Energy transferred.

Question 4

What is the energy transferred between the car’s brakes and its wheels when a car slows down?

Answer 4

Friction between the brakes and the wheel causes and energy transfer from kinetic to thermal.

Question 5

How do you calculate kinetic energy from an objects mass and speed?

Answer 5

Kinetic Energy = 1/2 x Mass(kg) x Velocity^2(m/s)

Question 6

How do you calculate Gravitational Potential Energy?

Answer 6

Gravitational Potential Energy = Mass(kg) x Gravitational Field Strength(N/kg) x Height(m)