Quick Assessment- Fundamentals

A fundamental quantity is so called because it

• cannot be measured directly

• is one of the few that make up all other quanitities

• has both magnitude and direction

• has magnitude only

Work is done whenever

• A force acts on a body

• A body is in motion

• The point of application of a force moves

• A body is inside a gravitational field

Acceleration may best be defined as

• The product of mass and velocity

• The rate of change of momentum

• The rate of change of speed

• The rate of change of velocity

The mass of a body

• is a measure of its inertia

• is the number of particles the body contains

• is the amount of space the body occupies

• is the same as its weight

Energy may be defined as

• The distance moved per unit force acting on a body

• The total work done on a body or system

• The ability to cause movement

• The total work done on a system

• T

A body is moving with uniform speed when

• There is no resultant force acting on it

• There are no frictional forces acting on it

• It is moving in a straight line

• It is travelling equal distances in equal time intervals

• t

In order for a body to accelerate

• it must be increasing speed

• There must be an unbalanced force acting on it

• it must be moving in a circle

• there must be no frictional forces acting on it

The potential energy of a body

• Depends on its location in a field

• Depends on its height above the ground

• is zero when it is moving

• Depends on the arrangement of its particles

A resultant force is best described as

• the algebraic sum of the forces acting on a body

• a single force that has the same effect as all the forces acting on a body

• the force that is equal but opposite to the reaction force on a body

• the force that is required to keep a body moving with uniform velocity

According to the law of conservation of energy

• When a body loses potential energy, it always gains the same amount of kinetic energy

• The energy in a system is continually being reduced by friction

• The total energy in a closed system is constant

• When work is done on a body, the total energy of a system decreases