Simple Machines Day 3

Which of these is NOT an example of a wedge?

• Scissors

• Teeth

• Bottle opener

• Knife

If it takes 1000 N to split a log in half, what is the minimum force needed with an axe with an AMA of 90 to cut it?

• 90,000 N

• 90 N

• 11.1 N

• 200 N

What is the IMA of this pulley?

• 1

• 1.5

• 2

• 3

Torque is...

• The same thing as force

• Any object rotating

• The rotational equivalent of force

• Always equal to F*r

What simple machines make up a screw?

• Inclined plane, lever, pulley

• Wheel and axle, inclined plane, wedge

• Wedge, wheel and axle, lever

• Inclined plane, pulley, wedge

You measure a simple machine to have an effort force of 10 N, and a load force of 55 N. Which of these must be true?

• IMA = 5.5

• Efficiency <= 100%

• AMA = 5.5

• The simple machine is a lever.

Energy put into a non-ideal simple machine comes out as:

• Useful work and thermal energy

• Thermal energy only

• Useful work only

• Useful work, thermal energy, and electrical energy

Which of these are considered "useful" work?

• A loud bang is produced.

• The simple machine gets warmer.

• The load is moved.

• Friction brings the simple machine to a halt.

A simple machine has an IMA of 10. However, it is measured to only multiply effort force by 6.5. Which of these is true?

• The simple machine is not ideal.

• Efficiency = 65%

• The machine is self-locking.

• No energy is destroyed by the machine.

True or False: If an object is accelerating, there must be force acting on it.

• True

• False