The Uncertainty Principle

Heisenberg's Uncertainty Principle tries to explain the potential duality of an electron behaving as either a particle or wave. 

Heisenberg's Uncertainty Principle

Heisenberg's Uncertainty Principle illustrates that an electron can behave as a particle or as a wave, but never both simultaneously. 

Concept: To illustrated this dual nature of an electron Heisenberg created his Uncertainty or Indeterminacy Principle 

4m

Concept: An electron has an uncertainty in its position of 630 pm. What is the uncertainty in its velocity? 

5m

The Uncertainty Principle Additional Practice Problems

A student is examining a bacterium under the microscope. The E. coli bacterial cell has a mass of = 0.500 (where a femtogram,fg , is 10-15 g) and is swimming at a velocity of v = 9.00 um/s, with an uncertainty in the velocity of 8.00 %. E. coli bacterial cells are around 1 um (10-6m ) in length. The student is supposed to observe the bacterium and make a drawing. However, the student, having just learned about the Heisenberg uncertainty principle in physics class, complains that she cannot make the drawing. She claims that the uncertainty of the bacterium's position is greater than the microscope's viewing field, and the bacterium is thus impossible to locate.

What is the uncertainty of the position of the bacterium? Express your answer numerically in meters.

Watch Solution

According to the Heisenberg uncertainity principle , if the uncertainity in the speed of an electron is 3.5 x 103 m/s, the uncertainity in its position (in m) is at least:

A) 66 m 

B) 1.7 x 10-8 m

C) 17 m

D) 2.1 x 10-10 m

E) 6.6 x 10-8 m

Watch Solution

According to the Heisenberg uncertainty principle, if the uncertainty in the speed of an electron is 3.5 x 103 m/s, the uncertainty in its position (in m) is at least (mass electron = 9.11 x 10-31 kg) __.

A) 1.7 x 10-8 m

B) 6.6 x 10-8 m

C) 17 m

D) 66 m

E) None of these choices is correct

Watch Solution

To what uncertainty (in m) can the position of a baseball traveling at 45.0 m/s be measured if the uncertainty of its speed is 0.10%? The mass of a baseball is about 0.145 kg.

a. 8.1 x 10-33 m

b. 5.6 x 10-15 m

c. 6.7 x 10-45 m

d. 5.9 x 10-14 m

e. 4.4 x 10-65 m

Watch Solution

An electron traveling at 3.7 x 10 5 m/s has an uncertainty in its velocity of 1.88 x 10 5 m/s. What is the uncertainty in its position.

Watch Solution

An electron has an uncertainty in its position of 552 pm. What is the uncertainty in its velocity?

Watch Solution

An electron has an uncertainty in its position of 190 pm. What is its uncertainty in its velocity?

  1. 272 x 103 m/s
     
  2. 1.12 x 105 m/s
     
  3. 521 x 105 m/s
     
  4. 4.21 x 102 m/s
     
  5. 305 x 103 m/s
Watch Solution

According to the Heisenberg uncertainty principle, if the uncertainty in the speed of an electron is 3.5 x 103 m/s, the uncertainty in its position (in m) is at least.

  1. 66 m
     
  2. 17 m
     
  3. 6.6 x 10-8 m
     
  4. 1.7 x 10-8 m
     
  5. 2.1 x 10-10 m
Watch Solution