Bernoulli principle
According to Bernoulli's principle, this faster moving air on the top has a lower pressure than the non-moving air on the bottom. With a greater pressure on the bottom of the paper there is also a greater force pushing up.

4 0

3 years ago

When measuring the diameter of a cylinder the following measurements are obtained.

Arlecino [84]

Answer:

a. 1.80 %

b. 0.60 %

c. 1.20 %

d. 0.60 %

e. 0.60 %

Explanation:

In order to calculate percent uncertainties in each case, we forst need to calculate the average value:

Average Diameter = (16.4 mm + 16.8 mm + 16.9 mm + 16.6 mm +16.8 mm)/5

Average Diameter = 16.7 mm

Now, the formula for percent uncertainty is:

% Uncertainty = (Uncertainty/Average) * 100 %

where,

Uncertainty = |Value - Average|

For Each Case:

a. 16.4 mm:

Uncertainty = |16.4 mm - 16.7 mm| = 0.3 mm

Therefore,

% Uncertainty = (0.3 mm/16.7 mm) * 100%

% Uncertainty = 1.80 %

b. 16.8 mm:

Uncertainty = |16.8 mm - 16.7 mm| = 0.1 mm

Therefore,

% Uncertainty = (0.1 mm/16.7 mm) * 100%

% Uncertainty = 0.60 %

c. 16.4 mm:

Uncertainty = |16.9 mm - 16.7 mm| = 0.2 mm

Therefore,

% Uncertainty = (0.2 mm/16.7 mm) * 100%

% Uncertainty = 1.20 %

d. 16.6 mm:

Uncertainty = |16.6 mm - 16.7 mm| = 0.1 mm

Therefore,

% Uncertainty = (0.1 mm/16.7 mm) * 100%

% Uncertainty = 0.60 %

e. 16.8 mm:

Uncertainty = |16.8 mm - 16.7 mm| = 0.3 mm

Therefore,

% Uncertainty = (0.1 mm/16.7 mm) * 100%

% Uncertainty = 0.60 %

7 0

3 years ago

Select all the correct answers.

chubhunter [2.5K]

Answer:

Water breaking down into hydrogen and oxygen is a decomposition reaction

Hydrogen and oxygen combining to form water is a synthesis reaction

Explanation:

A decomposition reaction is a chemical reaction that involves the breakdown of a chemical reactant entity into two or more simpler product fragments

Water H₂O undergoes a decomposition reaction by breaking down into hydrogen, H₂,, and oxygen, O₂, as follows;

2H₂O (l) → 2H₂ (g) + O₂ (g)

A synthesis reaction is a reaction that involves the chemical combination of two or more dissimilar molecules or atoms to produce a different compound or molecule

Water, H₂O, is formed by a synthesis reaction of hydrogen, H₂,, and oxygen, O₂, combining as follows;

2H₂ + O₂ → 2H₂O

5 0

3 years ago

Electric field lines always begin at _______ charges (or at infinity) and end at _______ charges (or at infinity). One could als

lesantik [10]

Answer:

Explanation:

By convention, the electric field lines (which are tangent to the direction of the electric field at a given point) always begin at positive charges, and finish at negative charges.

This is a consequence of the convention that states that the electric field has the direction of the trajectory of a positive test charge when released from rest in an electric field.

(As the positive charge would move away from positive charges and would be attracted by negative ones).

So, the combination of answers that is true is b) (positive, negative, positive).

3 0

3 years ago