MMechanics Flashcards
(47 cards)
25 ft/s East is an example of what?
Velocity
Every applied force is matched by a force that:
Is opposite in direction and equal in magnitude.
Give an example of thermal expansion:
Road buckling due to freezing water
In the English system, forces are measured in _________
Pounds
A vector is used to designate ______ and ___________
Size and direction
One equation for work?
Force x distance
What is energy?
The ability to do work
How much power is used when lifting a 30lb object a distance of 12 ft in 10 seconds?
Work = 30(12); 360/10= 36ft lb/sec
BTU is a measure of what?
Heat (British thermal unit)
In a machine that is 90% efficient, 10% shows up as what?
Heat (friction)
PSIA stands for:
Pounds per square inch, absolute
Lengthening the tubing in fluid power systems __________ the friction head.
Increases
One important difference between gas and liquids?
Gas can be compressed
The source of pressure exerted on an unconfined liquid is:
Gravity
How do you figure out absolute pressure from gauge pressure?
Add 14.7psi
A cam and follower mechanism changes rotary or linear motion to:
Reciprocating motion
When a simple machine is used to gain speed, it is at the expense of:
Force or effort
Name the 6 simple machines:
Lever, pulley, wedge, wheel and axel, inclined plane, screw.
Which class of lever changes the direction of force?
Class 1 (see-saw)
Actual mechanical advantage is less than ideal because of:
Internal friction
A combo of 2 or more machine parts is called a:
Mechanism
A bell crank has ___ fixed point(s) and ___ movable pivot point(s)
1;2
The input motions of a cam and follower are either:
Rotary or linear
The electric motor is the ________________ of a machine
Prime mover
