Energy and Momentum

Question 1

What is Work

Answer 1

Its the energy that a force gives an object when it causes it to move

Question 2

What is positive work
3 points

Answer 2

Its when the applied force is in the same direction as the objects displacement

• also when the obj displacement is between 0 and 90 to the applied force
• objects height or speed increase

Question 3

What is negative work

Answer 3

When objects move in a direction opposite to the applied force say due to friction

-causes loss of kinetic energy
- neg work is exerted at angles between 90 and 180, opposite to objects direction
-obj slows down or loses height

Question 4

When does 0 work occur

Answer 4

• When the direction of the objects displacement is exactly 90 to the applied force

** reminder : carrying smth doesnt do any work unless you pick it up **

Question 5

What is energy

Answer 5

The ability to do work

Question 6

Kinetic energy

Answer 6

Associated with motion

Question 7

Potential energy

Answer 7

Associated with position
- Its the stored energy an object has that can be transformed into another form of energy

Question 8

What is the work-energy theorem

Answer 8

When a net force acts on an object the object accelerates
- This means that the force does work on an object and its kinetic energy changes
therefore TOTAL work done = CHANGE in kinetic nrg

Question 9

What is the law of conservation of energy

Answer 9

It describes that the sum of kinetic energy and potential energy (which equals total mechanical energy) remains constant in any closed or isolated system

NOTE : the Et is conserved but the Ek and Eg may increase or decrease accordingly