DeepnarainWorkandEnergyAPP1

Energy is only constant within a __________ system

• open

• closed

What does a closed system mean?

• There are no external interactions (forces)

• There are no internal interactions (forces)

If forces are all internal, _____________

• total energy will stay the same

• total energy will not stay the same

What is energy?

• ability to do work

• change in work

• displacement

• net force

What is the slope of a force vs position graph?

• velocity

• spring constant

• acceleration

• position

What is the area under a force vs position graph?

• Work

• Velocity

• Acceleration

• Position

Calculate the work done on a box that moves 10 m to the right with a force of 15 N applied to it (towards the right).

• 10(15) = 150 J

• 10(15)/2 = 75 J

• 15(2) = 30 J

• 10(150) = 1500 J

Calculate the Work done on an object whose displacement is +15 meters and whose force acting on the object at a 30 degree angle is 10 N.

• 30(10)(15) = 4500 J

• 10(15)cos(30) = 23 J

• 15(11)cos(30) = 25 J

• 10(15) = 150 J

When displacement is in the same direction as force,

• positive work is done

• negative work is done

• zero work is done

When displacement is perpendicular to the force applied

• No work is done

• Positive Work is done

• Negative Work is done