2. Work is only done by a force on an object if the force causes the object to move in the direction of the force. Objects that are at rest may have many forces acting on them, but no work is done if there is no movement.

3. Work, by definition, is the product of the force exerted on an object and the distance the object moves in the direction of the force. W = F·d Work is a scalar quantity.

4. The SI unit of work is the joule, named in honor of James Prescott Joule James Prescott Joule James Prescott Joule James Prescott Joule. One joule, J, of work is the work done when 1.0 N of force is applied through a distance of 1.0 m.

5. Power, by definition, is the time rate of doing work; or the time rate transfer of energy. P = W / tP = W / tP = W / tP = W / t Power is a scalar quantity.

6. The SI unit of power is the Watt, named in honor of James Watt James Watt James Watt James Watt. One watt, W, of power is the power achieved when 1.0 J of work is done or 1.0 J of energy is transferred in a time of 1.0 s.

7. Energy the ability (capacity) to do work Energy comes in many forms: mechanical, electrical, magnetic, solar, thermal, chemical, etc... thermal, chemical, etc... The SI unit of energy is the joule. Energy, like work and power, is a scalar.

8. Work-Energy Theorem the net work done on an object is equal to its change in kinetic energy

9. Kinetic Energy depends on two things: mass and speed The amount of kinetic energy the cart has is equal to the amount of work you do to get the cart moving A cart at rest has NO Kinetic energy Applying a force can give the cart speed, and therefore kinetic energy. Applying a greater force increases the speed and therefore the kinetic energy Increasing the mass also increases kinetic energy because it takes even more force to push.

10. Kinetic Energy energy of motion All moving objects that have mass have kinetic energy. KE = 1/2 mv 2 m - mass of the object in kg v - speed of the object in m/s KE - the kinetic energy in J

11. Click here to explore energy, work, and the here Work-Energy Theorem in more depth.

12. Learn more about the Work-Energy Theorem herehere and here. here A net force causes an object to change its KE because a net force causes an object to accelerate, and acceleration means a change in velocity, and if velocity changes, KE changes.

13. Potential Energy Gravitational potential energy depends on an objects mass and height Objects with potential energy don’t use their energy until they start moving. The further the object is from the ground the more potential energy it has Chemical potential energy is energy stored in the form of chemical bonds.

14. Potential Energy energy of position or condition gravitational potential energy PE g = mgh m - mass of object in kg m - mass of object in kg g - acceleration of gravity in m/s 2 g - acceleration of gravity in m/s 2 h - height of object, in m h - height of object, in m PE – gravitational potential energy in J

15. Potential Energy energy of position or condition elastic potential energy PE elastic = ½ kx 2 k – elastic constant in N/m k – elastic constant in N/m x - elongation or compression in m x - elongation or compression in m PE elastic – elastic potential energy in J PE elastic – elastic potential energy in J Click here to investigate elastic constants. here