2- Mechanics

Question 1

Acceleration (definition)

Answer 1

The rate of change of velocity in a particular direction. Vector quantity.

Question 2

Acceleration (equation)

Answer 2

a = v/t

Question 3

Angular velocity (definition)

Answer 3

The rate of change of angle of an object undergoing uniform circular motion at constant speed

Question 4

Angular velocity (equation)

Answer 4

w = ∆θ/∆t

Question 5

Law of conservation of linear momentum

Answer 5

The total linear momentum of a system of interacting particles remains constant provided there is no resultant external force (i.e. the system is isolated)

Question 6

Centripetal acceleration (definition)

Answer 6

Acceleration of an object moving at constant speed in uniform circular motion. Speed is constant but direction of velocity is changing, so it’s accelerating

Question 7

Centripetal acceleration (equation 1)

Answer 7

a = v^2/r

Question 8

Centripetal acceleration (equation 2)

Answer 8

a = 4π^2r/T^2

Question 9

Elastic collision

Answer 9

Collisions in which no energy is gained or lost, ie. Collisions between atoms and molecules.

Question 10

Energy

Answer 10

The work that has been done on a body. Also equal to the amount of work that the body is capable of doing.

Question 11

Gravitational potential energy

Answer 11

mg∆h

Question 12

Impulse

Answer 12

The resultant force acting on the object times time for which this force acts. It is equal to change of momentum of the object. Vector quantity

Question 13

Impulse (equation)

Answer 13

F∆t and m∆v

Question 14

Inelastic collision

Answer 14

Collisions in which the objects involved in the collision lose energy (e.g. to thermal energy or to sound). All laboratory collisions are inelastic.

Question 15

Kinetic energy

Answer 15

1/2mv^2

Question 16

p = mv

Answer 16

Linear momentum

Question 17

Newton’s first law (definition)

Answer 17

A body in motion stays in motion unless an external force acts

Question 18

Newton’s second law (equation 1)

Answer 18

F = ma

Question 19

Newton’s second law (equation 2)

Answer 19

F = ∆p/∆t

Question 20

Newton’s third law (definition)

Answer 20

Two interacting bodies exert equal and opposite forces on each other

Question 21

Power (equation)

Answer 21

P = ∆W/∆t

Question 22

Power

Answer 22

Rate of doing work, which is the same as the rate of transferring energy. Scalar quantity.

Question 23

Translational equilibrium

Answer 23

When the resultant force on the object is zero. Object is either at rest or moving with constant (uniform) velocity in a straight line

Question 24

Work

Answer 24

Force times component of displacement in direction which force acts

Question 25

Work (equation 1)

Answer 25

Force x distance

Question 26

Work (equation 2)

Answer 26

W = Fscosθ

Question 27

W = mg

Answer 27

Weight

Question 28

Momentum, energy

Answer 28

In an elastic collision which out of: momentum, energy, are conserved?

Question 29

Principle of conservation of energy

Answer 29

Energy cannot be created or destroyed, it just changes from one type to another

Question 30

Work (equation 3)

Answer 30

W = ∆Ek