Mechanical Force Notes

Mechanical Force Notes

1_____________ is a push or a pull

2Force is a push or a pull.3Effect of force depends on:4Effect of force depends on:1. Magnitude (strength)2. Direction of the force5Force is measured in:6Pounds English System

Newtons SI (System International)

7Force can be measured by spring balances or ____________.8Force can be measured by spring balances or scales

9___________ forces equal and opposite.

__________ forces one side stronger. Gives a NET FORCE.10Balanced forces equal and opposite.

Unbalanced forces one side stronger. Gives a NET FORCE.

11___________ - shows only magnitude (strength)

Examples:12Scalars - shows only magnitude (strength)

Examples: Temperature, Elapsed time, pressure and mass.

13__________ - shows both magnitude and direction.

Examples:14Vectors - shows both magnitude and direction.

Examples: Force, displacement, velocity, acceleration and momentum.15Vectors have magnitude and direction

Vector lines are drawn with an arrow.

___________ = magnitude of vector (strength)

___________ = direction the force is acting.17Vector lines are drawn with an arrow.

Length of arrow = magnitude of vector (strength)Direction of arrow = direction the force is acting.

182 or more forces in the same direction you can add to get the total force (net force).

2 or more forces in the opposite direction, you subtract to get the net force.19If forces dont act along the same line you cannot add or subtract. You have to graph and measure the resulting line (or use trigonometry).

You have 30 lbs pulling North and 40 lbs pulling East. What is the resulting force?201. Chose a scale (say 1 cm 10 lbs)2. Graph the 2 forces at the correct angle matching the head of one line to the tail of the other line.3. Draw the resultant line. Measure that line and use your scale to determine its magnitude.21_________ is force in rotation mechanical systems.

It is measured in ___________ or __________

T=F x L22Torque is force in rotation mechanical systems.Measured in lb ft or N m

T = F x L

23Torque = _____________ x _____________

____________ is the shortest distance from the rotation axis to the line of action.24Torque = applied force x lever arm

The lever arm is the shortest distance from the rotation axis to the line of action.25If the lever arm is 12 inches (1 foot) and you use 40 lbs of force to turn it find the torque:26T = F x L

40 lbs x 1 ft = 40 lb ft27You need 80 Nm of torque to turn a bolt. You can apply 100 Newtons of force. How long of a wrench (lever arm) do you need?28T = F x L

80 = 100 x L

80/100 = .8m T = .8 m29