Conservation Of Energy

Question 1

States that something is conserved; that is, something remains constant under certain condition

Answer 1

Conservation Law

Question 2

Mass and electric charge, as well as energy, seems to be conserved in all processes except under most extreme conditions

True or False

Answer 2

True

Question 3

When work is done on a system by nonconservative forces, the total mechanical energy does not change.

True or False

Answer 3

False

Question 4

One kind of frictional force is air resistance

True or False

Answer 4

True

Question 5

The two forces on a raindrop

Answer 5

The force of gravity and air resistance

Question 6

As the drop’s velocity increases, the air resistance also increases

True or False

Answer 6

True

Question 7

The drop stops accelerating and continues to fall with a constant velocity

Answer 7

Terminal velocity

Question 8

When the drop reaches terminal velocity, its kinetic energy does not remain constant

True or False

Answer 8

False

Question 9

If potential and kinetic energy is changed to thermal energy then total mechanical energy is not conserved

True or False

Answer 9

True

Question 10

Friction changes mechanical energy into sound energy

True or False

Answer 10

True

Question 11

Ideal strings have no mass but does not obey Hooke’s law

True or False

Answer 11

False

Question 12

Is the minimum speed that an object of mass m requires to leave a larger object of mass M so that mass m cannot return due to gravitational attraction alone

Answer 12

Escape Speed

Question 13

Is a device that changes the magnitude or direction of an applied force

Answer 13

Machine

Question 14

The word ideal in IMA implies that IMA is perfect and thus unrealistic

True or False

Answer 14

True

Question 15

Is defined as the output force when friction is present, divided by the input force

Answer 15

Actual mechanical advantage (AMA)

Question 16

The two basic classes of simple machines:

Answer 16

Inclined planes and levers

Question 17

Wedges, screws, and ramps are called

Answer 17

Inclined planes

Question 18

Two inclined planes placed base to base

Answer 18

Wedge

Question 19

Is a metal shaft surrounded by a hellically coiled wedge

Answer 19

Screw

Question 20

A screw with a small pitch must be turned more times than a screw with a large pitch

True or False

Answer 20

True

Question 21

Is usually a rigid bar that turns around a pivot, the fulcrum. In use an input or effort force

Answer 21

Lever

Question 22

The fulcrum is between the resistance and the effort forces examples are seesaws, crowbars, and scissors

Answer 22

First-class levers

Question 23

The resistance is between the fulcrum and the effort force examples are hinged doors, wheeled tote bags, and nutcrackers

Answer 23

Second-class levers

Question 24

The effort force is between the fulcrum and the resistance. Broom and tweezers are common examples

Answer 24

Third-class levers

Question 25

Are modified levers

Answer 25

Wheels

Question 26

Is a grooved wheel that turns on axle

Answer 26

Pulley