force is a push or pull while a net force is the combination of all acting forces

what is the difference between force and net force on an object

tension

what name is given to the stretching force that occurs in a spring or rope being pulled

magnitude and direction

what two quantities are necessary to determine a vector quantity

vector quantity needs both magnitude and direction while scalar quantity needs only magnitude

how does a vector quantity differ from a scalar quantity

force

give an example of a vector quantity

time, area, or volume

give an example of a scalar quantity

20 N

how much tension is in a rope that holds up a 20 N bag of apples at rest

net force is 10 N to the right

what is the net force on a box that is being pulled to the right with a force of 40 N and pulled to the left force of 30 N

the vector sum of all the forces that act on an object equal zero

what is the net force on an object at rest

each arm supports half your weight

when you do pull-ups and you hang at rest, how much of your weight is supported by each arm

90 degrees

support force is perpendicular to the surface

support force is perpendicular to the surface

what is the angle between a support force and the surface an object rests upon

support (normal) force and gravity (weight)

what two forces compress a spring inside a weighing scale when you weigh yourself

the sum will equal your weight when you are at rest

when you are at rest and supported by a pair of weighing scales, how does the sum of the scale reading compare with your weight

yes – if it moves at constant speed in a straight line

can an object be moving and still be in equilibrium? defend your answer

both forces are equal in magnitude, but in opposite directions

the net force is zero

if you push a crate across a factory floor at constant speed in a constant direction, what is the magnitude force of friction on the crate compare with your push

static – rest

dynamic – constant speed in a straight line

dynamic – constant speed in a straight line

distinguish between static equilibrium and dynamic equilibrium

resultant – the sum of the two vectors

according to the parallelogram rule for two vectors, what does the diagonal of a constructed parallelogram represent

downward force is weight

two upward forces are tension in rope

two upward forces are tension in rope

consider the suspension of Nellie in Figure 2.11 (pg 21). Name the three forces that act oh her. What is evidence that they cancel to zero

rope tensions are greater

consider Nellie in Figure 2.12 What changes in rope tension occur when ropes make a grater angle with the vertical

resultant of both rope tensions is equal in magnitude and opposite in direction to the vector representing her weight

when Nellie hangs from ropes at different angles as shown in Figure 2.13 how does the vector resultant of the two rope tensions compare with her weight