WorksheetsL11: Machines
Total questions: 35
Worksheet time: 49mins
Which statement best defines a machine?
Only has one motor
Makes work easier
Decreases total amount of work for a job
Reduces force and distance required for work
Work Input
Work done by machine
Resistance Force
Applied force
Work Output
Work done by machine
Effort Force
Applied Force
Mechanical Efficiency
% of Work Output to Input (always less than 100)
Number of times machine multiples force
Amount of work done by a machine
How fast the machine works
A machine is never 100% efficient (2nd Law of Thermodynamics) due to...
Heat transfers out due to friction
Humans aren't strong enough (applied force)
There is not enough renewable energy available
Machine design needs more technology
Mechanical Advantage
# of times machine multiplies applied force
Amount of work done
(force * distance)
How fast the machine works
How well machine overcomes friction (ratio of work output to input)
Mechanical Advantage = 1
Machine multiples FORCE
Machine helps
change DIRECTION
Machine extends DISTANCE
of applied force
Mechanical Advantage > 1
(greater than 1)
Machine multiples FORCE
Machine helps
change DIRECTION
Machine extends DISTANCE
of applied force
Mechanical Advantage < 1
(less than 1)
Machine multiples FORCE
Machine helps
change DIRECTION
Machine extends DISTANCE
of applied force
What is NOT factored into IDEAL MECHANICAL ADVANTAGE?
Gravity
Mass
Weight
Friction
A flat sloping surface that connects lower and higher elevations. It makes moving objects easier.
wedge
screw
lever
inclined plane
Stairs
wedge
pulley
inclined plane
wheel and axle
Incline plane with best mechanical advantage (MA)
short and high incline
long and high incline
long and low incline
Skateboard jump
inclined plane
fulcrum
force
lever
A simple machine that consists of a rigid bar that pivot on a fixed point to dislodge or lift a load
lever
pulley
wheel and axle
fulcrum
Which lever in the image has a better advantage?
Fulcrum closer to load (right)
Fulcrum farther from load (left)
Both have same advantage.
Which class lever?
1st Class
2nd Class
3rd Class
4th Class
Which class lever?
1st Class
2nd Class
3rd Class
4th Class
Which class lever?
(Load = RESISTANCE)
1st Class
2nd Class
3rd Class
4th Class
Which class lever?
1st Class
2nd Class
3rd Class
4th Class
Which class lever?
1st Class
2nd Class
3rd Class
4th Class
Which class lever?
1st Class
2nd Class
3rd Class
4th Class
What is the "fixed point" on which a lever pivots?
screw
wheel and axle
resistance
fulcrum
What is the ADVANTAGE of this moveable pulley system?
1
2
3
No advantage
Which statement is true about a FIXED PULLEY?
Rope is under pulley attached to load
Mechanical advantage MULTIPLIES FORCE
Mechanical advantage helps CHANGE DIRECTION
Mechanical advantage is greater than 1
Grooved wheel (freely spins) holding a rope to raise/lower/move a load
Wheel & Axle
Pulley
Lever
Incline Plane
Which screw in the image will have the greater mechanical advantage?
Left (threads far apart)
Right (threads closer together)
Both have same mechanical advantage
There is no mechanical advantage to the screw
Which simple machine splits or separate objects?
inclined plane
screw
wedge
lever
Which wedge has the greatest mechanical advantage?
Thin and Long
Thin and Short
Wide and Long
Wide and Short
The bow (front) of the boat splits the water helping the boat move through the water. Which simple machine is the bow?
wedge
screw
ramp
lever
Which simple machine is a door knob?
wheel and axle
inclined plane
pulley
wedge
The WHEEL and AXLE with the greatest MECHANICAL ADVANTAGE is...
BIGGER WHEEL to axle
BIGGER AXLE to wheel
Same size for both the wheel and axle
A wheel that spins around a rod (axle) to move or lift a load
wheel and axle
inclined plane
pulley
wedge
