Chapter 4 Test Flashcards
A machine is a device that makes doing work easier by _______, _______, or ________
increasing the force applied to an object
changing the direction of an applied force
increasing the distance over which a force can be applied
a compound machine is a machine that…
is a combination of two or more simple machines
an ideal machine is a theoretical machine in which…
the amount of work you put into the machine is equal to the amount of work you get out of the machine
efficiency is the ratio of ______ to ______, expressed as a percentage
output work done by the machine
input work done on the machine
mechanical advantage is the ratio of ______ to the ______
output force exerted by a machine
input force applied to the machine
power is the rate at which ______
energy is converted
work is the…
transfer of energy when a force is applied over a distance
energy is…
the ability to cause change
potential energy is the energy that is stored due to ______
the interactions between objects
kinetic energy is the energy a ______ has because of its ______; determined by the ______ and ______ of the object
moving object
motion
mass
speed
a calorie is what ______ is measured in
energy in food
what is the formula for work
W = F d
what is the formula for power
P = E / t
energy (J)/ time (s)
what is the formula for general mechanical advantage
MA = Fout / Fin
what is the formula for efficiency
EFF = Wout / Win x 100
what is the formula for kinetic energy
KE = 1/2m v^2
what is the formula for gravitational potential energy
GPE = m g h
What formula is this:
IMA = Lin/Lout
lever
What formula is this:
IMA = l/h
inclined plane
What formula is this:
IMA = rw/ra
wheel and axle
What formula is this:
IMA = l/w
wedge
what are the different forms of energy
thermal
electrical
nuclear
sound
radiant (light)
chemical
state the law of conservation of energy
energy cannot be created or destroyed but changed into other forms
how many calories are in:
1g fat
1g protein
1g carbohydrate
1g fat: 10C
1g protein: 5C
1g carbohydrate: 5C
