Fun
An inclined plane is a simple machine that is a flat surface that is ___________ at one end.
higher or raised
Joules
Unit of measurement for Work and Energy
Using a machine allows us to use ____________ force to move something.
less
Using a screw takes ______________ force than pounding a nail
less
If Alan is on the right and George is on the left of a box, what needs to happen to make the box move to the right?
George needs to push the box to the right with more force than Alan.
You apply a force of 18 N on to the end of a lever to open a paint can lid. The resistance of the lid is 9 N. Calculate the MA if it equals output force / input force
MA= 0.5
9N / 18N = 0.5
Newtons
Unit of measurement for Force
Usually expressed as a percentage.
Mechanical Efficiency
You do 20 J of work in pushing a crate up a ramp. If the output work from the inclined plane is 11 J, then what is the efficiency of the inclined plane?
Efficiency = Work Out/ Work in x 100
55%
What type of simple machine is found on the cap of a pickle jar?
A boy is ready to drop a 1.6 kg water balloon out of a window onto his sister below. The boy is holding the balloon 11.3 m off the ground. How much potential energy does the balloon have just before the boy drops it?
Round to nearest tenth.
177.2 Joules
What is the equation to calculate ideal mechanical advantage of an inclined planed?
Length of ramp / height of ramp
It takes 600 J of work to lift a crate straight up but 1,200 J to push that crate up a ramp to the same height. What is the efficiency of the ramp?
Work Out/ Work In x 100 = 600 / 1200 x 100 = 50%
Which body parts acts as the fulcrums of levers?
a. lungs
b. joints
c. kidneys
d. brain
b. joints
How does a single fixed puled, like the one seen here, help you do work?
a. changes the direction of the forceb. increases the amount of applied force
c. decreases the amount of applied force
d. allows you to pull the rope a shorter distance
a. changes the direction of the force
True or false: a ball on the ground has more potential energy than a ball on a hill.
False
Like vases are placed on different shelves. Vase A on shelf 2 and Vase B on shelf 4
Which object has more GPE?
Vase B
KE = 1/2mv2
A student walks to school at a speed of 2.0m/s. If the student's mass is 50kg, what is the kinetic energy from the student's forward motion.100 J
Using a lever, Joe is able to lift a 10,000 N car off of the ground with a force of 1000 N. What is the mechanical advantage of the lever?
MA of lever = Output Force / Input Force
10
What is the equation for Work?
Work = force x distance
What are two ways simple machines make work easier?
Decrease amount of input force
AND
increasing the distance over which the input force is applied.
What is the unit on mechanical advantage?
The length of a ramp is 15 meters and the height of the ramp is 4 meters. Calculate the IMA of the inclined plane.
3.75
How can you decrease the effort force needed to push a weight to the top of the ramp?
a. cover the surface with carpet
b. increase the length of the ramp
c. increase the height of the ramp
d. decrease the length of the ramp
b. increase the length of the ramp
You apply a force of 18 N to a dresser and move it 3.0 m. How much work did you do on the dresser?
a. 54 J
b. 6.0 J
c. 21 J
d. 27 J
W= F x d= 18N x 3.0m = 54J