Energy transformations, simple machines, and forces review

What is the Law of Conservation of Energy?

• This law states energy is created but not destroyed.
• This law states that energy is created, destroyed, and changes form.
• Energy is not created, destroyed, 
• Energy is neither created or destroyed; it is just transformed.

What is an energy transformation?

• When energy changes from one form to another.
• When energy stays the same.
• When the amount of energy decreases rapidly.
• When the amount of energy transfers to a new location.

An object at rest will change its motion when

• acted upon by balanced forces.
• acted upon by unbalanced forces.
• the object is at rest.
• the object has a low mass.

What is the result of the unbalanced forces in this picture?

• the people will move to the right with a net force of 50 g
• the people will move to the left with a net force of 50 g
• the people will move to the left with a net force of 50 N
• the people will move to the left with a force 50 meters/second

How do simple machines affect work?

• simple machines change distance
• simple machines change the speed and direction of work being done
• simple machines change the amount, direction, or distance of the applied force
• simple machines only increase distance and force applied

What is true about balanced forces?

• Balanced forces have a net force of zero and change the object's motion.
• Balanced forces have a net force of zero and cause no change in motion.
• Balanced forces have a net force not equal to zero.
• Balanced forces are equal to unbalanced forces in the conservation of mass.

Unbalanced forces

• have a net force not equal to zero
• have a net force equal to zero
• have a net force equal to balanced force
• create no change in motion

What increases the advantage of an inclined plane?

• a steep ramp is best
• a short, steep ramp is best
• a long, less steep ramp is best
• a long, steep ramp is best

How can you increase the mechanical advantage of a pulley system?

• Increase the number of pulleys & the rope length
• decrease the number of pulleys and the rope length
• less pulleys and more rope
• more pulleys and less rope

How does a single pulley change work?

• a single pulley changes the speed
• a single pulley changes the terms of the load
• a single pulley changes the direction of the force
• a single pulley changes the mass of the load