Physics (Reviewer)

When does a measurement have a high degree of accuracy?

• When it is reported with many significant figures

• When it can be easily reproduced

• When it is made using expensive, calibrated tools

• When it is close to the true value of the quantity being measured

Answer explanation

An accurate measurement is one that precisely reflects the actual value, being minimally different from the true quantity.

hat is the standard unit of time?

• The minute

• The hour

• The second

• The day

Answer explanation

The standard unit of time is the second, as it provides a consistent and precise measure of time intervals that can be reproduced universally.

When does a vibration or cycle occur?

• Throughout the measurement

• At random intervals

• During the period

• At the frequency

What is the relationship between period and frequency?

• They are directly proportional

• They are unrelated

• They share a constant sum

• They are inversely proportional

Answer explanation

As defined in the passage, the period and frequency are reciprocals, meaning if one value increases the other must decrease.

What is the formula relating period and frequency?

• Tf = 1

• T + f = 1

• f = 1/T

• T = 1/f

Answer explanation

As stated directly in the passage, the period T and frequency f are reciprocals related by this fundamental formula.

What is the condition for an object to be in equilibrium?

• The object must be accelerating

• The net force on the object must equal zero

• The object's velocity must be increasing

• The object must be rotating at a constant rate

Answer explanation

For an object to be in equilibrium, the vector sum of all external forces acting on it must be zero, so that Newton's first law applies and the object's state of motion is unchanged.

What is the SI unit for frequency?

• Meters per second

• Joules

• Hertz

• Newtons

Answer explanation

The Hertz (Hz) is the standard international unit used to express frequency, with one Hertz equaling one cycle per second.

When does an object have zero net external force?

• When it is accelerating

• When it is at rest

• When it is in a state of uniform circular motion

• When it has a constant velocity

Answer explanation

If an object's velocity is constant, then the vector sum of all external forces acting on it must be zero, in accordance with Newton's first law.

What is the graphical method of vector addition?

• Applying trigonometric functions to calculate the x and y components of vectors

• Experimentally measuring the net force of concurrent vectors using a force table

• Determining vector directions relative to a positive x-axis

• Using a triangle or parallelogram to determine the magnitude and direction of the resultant vector of two or more forces

Answer explanation

The graphical method employs geometric constructions like triangles or parallelograms to visually represent the addition or combination of vectors. By connecting the vectors head to tail, their resultant magnitude and direction can be inferred.

When does the parallelogram method apply to vector addition?

• When experimentally measuring vector combinations

• When adding two or more vectors graphically

• When vectors are not concurrent

• Only when vectors are perpendicular

Answer explanation

The parallelogram method extends the triangle method to graphically determine the resultant of two or more vectors by connecting the vectors head to tail to form a parallelogram.