Mastery Machine

In the chemical reaction 4 A + 3 B → 5 C + 9 D, if 14 moles of A react with 15 moles of B, what is the limiting reactant?

• Substance A

• Substance B

• Substance C

• Substance D

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which difference between the atoms makes them different elements?

• The fluorine atom has 2 energy levels, and the sodium atom has 3 energy levels.

• The fluorine atom has 9 protons, and the sodium atom has 11 protons.

• The fluorine atom has 10 neutrons, and the sodium atom has 12 neutrons.

• The fluorine atom has 7 valence electrons, and the sodium atom has 1 valence electron.

Tags

NGSS.MS-PS1-1

If a machine has a mechanical advantage of 10 and the input force is 50 N, what is the output force?

• 500 N

• 100 N

• 5 N

• 50 N

Tags

DOK Level 2: Skill/Concept

GA.SPS8.d.

• You must use the formula for force and calculate the acceleration.

• You must use the formula for work and calcuate the distance

• You must use the formula for speed to calculate the distance each car traveled.

• You must calculate the input force so you can determine the output force for mechanical advantage.

Tags

NGSS.MS-PS3-1

If a machine has a mechanical advantage of 5 and the input force is 20 N, what is the output force?

• 100 N

• 4 N

• 25 N

• 5 N

A pulley system lifts a 200 kg mass with an input force of 500 N. What is the mechanical advantage of the system?

• 4

• 0.4

• 2.5

• 1

Tags

NGSS.MS-PS2-2

Which of the following best describes the principle of a lever?

• A lever amplifies an input force to provide a greater output force.

• A lever reduces the input force to provide a smaller output force.

• A lever changes the direction of the input force without changing its magnitude.

• A lever stores energy for later use.

• 1000 N

• 10 N

• 100 N

• 1 N

Tags

NGSS.MS-PS2-5

What is the efficiency of a machine that does 200 J of useful work with an input of 250 J?

• 80%

• 100%

• 50%

• 125%

A machine requires 500 J of energy to perform 400 J of work. What is the efficiency of the machine?

• 80%

• 100%

• 125%

• 50%