Mechanics

Question 1

Uniform accelerated motion

Answer 1

Velocity is changing. Acceleration is constant

Question 2

For projectile motion, if acceleration is zero throughout flight, what is horizontal velocity?

Answer 2

Constant

Question 3

Newton’s second law

Answer 3

Force equals mass times acceleration

Question 4

Newton’s first law

Answer 4

Force must be applied for an object to move

Question 5

Newton’s third law

Answer 5

For every action there is an equal but opposite reaction

Question 6

If there is no force but object is moving, velocity must be

Answer 6

Constant

Question 7

If masses are different will the action reaction be the same?

Answer 7

No

Question 8

What kind of friction is rolling resistance?

Answer 8

Static friction

Question 9

True or false action reaction pairs work on same objects

Answer 9

False

Question 10

Kinetic friction is always what to velocity?

Answer 10

Parallel and opposite

Question 11

True or false coefficient of static friction is always greater than coefficient of kinetic friction

Answer 11

True

Question 12

For an inclined plane what is the force due to gravity?

Answer 12

Mg sin theta

Question 13

What do pulleys change the direction of?

Answer 13

Tension

Question 14

What is the center of mass?

Answer 14

Point where object acts as a single particle

Question 15

What is center of gravity?

Answer 15

Point where total gravitational force on the system can be considered to act

Question 16

What is uniform circular motion?

Answer 16

Object moving in a circular path with its speed held constant

Question 17

Why is velocity not constant in uniform circular motion?

Answer 17

Direction is constantly changing

Question 18

In uniform circular motion, velocity is always what to its path?

Answer 18

Tangent

Question 19

In UCM, where does acceleration point?

Answer 19

Center of circle. Velocity and acceleration are always perpendicular to each other

Question 20

What provides centripetal force?

Answer 20

Gravity and tension force

Question 21

What is centripetal force?

Answer 21

Net force directed toward the center

Question 22

What dies tangential acceleration change?

Answer 22

Speed making the object not in UCM

Question 23

In tangential acceleration, where does speed start to decrease?

Answer 23

As it rises to the top of the circle and opposed to the velocity vector

Question 24

What is torque?

Answer 24

Measure of force to make an object spin or rotate

Question 25

What is the fulcrum?

Answer 25

The center of turning

Question 26

If there is no torque, what cannot be decreased?

Answer 26

Rotational speed

Question 27

When is max torque reached?

Answer 27

When the angle equals 90 degrees

Question 28

For torque, clockwise is

Answer 28

Positive

Question 29

For torque counterclockwise is

Answer 29

Negative

Question 30

If the force acts at the pivot, what is the torque?

Answer 30

Zero

Question 31

What is the lever arm perpendicular to in torque?

Answer 31

Line of action of force

Question 32

What is work equal to?

Answer 32

Work equals distance times force, when force and distance are in the same direction

Question 33

What is the unit for work?

Answer 33

Joule

Question 34

What kind of forces always do zero work?

Answer 34

Perpendicular

Question 35

When is W= Fdcos used?

Answer 35

Force is constant

Question 36

What is power?

Answer 36

Measures how fast work gets done

Question 37

What is the unit for power?

Answer 37

Watt (Joules/sec)

Question 38

How much is one horsepower?

Answer 38

750 watts

Question 39

What is gravitational potential energy?

Answer 39

Moving a object higher or lower. It is opposite of work done by gravity

Question 40

Work done by gravity depends mainly on

Answer 40

Height

Question 41

If there is less effort force, what must be covered to satisfy work requirements?

Answer 41

Larger distance

Question 42

What is mechanical advantage?

Answer 42

Resistance force over effort force. Use the factor to find amount of force required without the machine

Question 43

What is resistance force?

Answer 43

Force applied if no machine were being used

Question 44

What is efficiency?

Answer 44

Degree to which friction and other factors reduce actual work output of machine from its theoretical max

Question 45

What is the equation for efficiency?

Answer 45

Work output/ energy output

Question 46

What can you use efficiency for?

Answer 46

Figuring out what % of energy is being lost

Question 47

What is impulse?

Answer 47

Force X time

Question 48

Momentum changes are

Answer 48

Equal but opposite

Question 49

What is equation for linear momentum?

Answer 49

P= my

Question 50

Is KE conserved in an elastic collision?

Answer 50

Yes

Question 51

Is KE conserved in an inelastic collision?

Answer 51

No

Question 52

What is a perfectly inelastic collision?

Answer 52

When objects stick together after colliding

Question 53

What does inelastic collisions result in?

Answer 53

Max possible loss of KE

Question 54

What is the rate of change for angular momentum?

Answer 54

Torque

Question 55

What is rate of change for linear momentum?

Answer 55

Force