Ib Physics Hl Topic 1 To 4

1. 1.1.1: State and compare quantities to the nearest order of magnitude.

If quantity is between 2 and 3, round to the nearest order of magnitude.

If quantity > 3.16, round to next order of magnitude.

If quantity < 1, round to previous order of magnitude.

If quantity has a decimal value, always round up to the next order of magnitude.

When comparing quantities to the nearest order of magnitude, it is important to follow the rule that if the quantity is greater than 3.16, it should be rounded up to the next order of magnitude. This helps simplify the comparison and estimation process.

Explanation

When comparing quantities to the nearest order of magnitude, it is important to follow the rule that if the quantity is greater than 3.16, it should be rounded up to the next order of magnitude. This helps simplify the comparison and estimation process.

2. State ratios of quantities as differences of orders of magnitude.

The ratio of the diameter of the hydrogen atom to its nucleus is about 100, or a difference of two orders of magnitude.

The ratio of the diameter of the hydrogen atom to its nucleus is about 10^2, or a difference of three orders of magnitude.

The ratio of the diameter of the hydrogen atom to its nucleus is about 10^-5, or a difference of five orders of magnitude.

For example, the ratio of the diameter of thehydrogen atom to its nucleus is about 105, or adifference of five orders of magnitude.

The concept of stating ratios of quantities as differences of orders of magnitude is exemplified by the significant difference between the diameter of the hydrogen atom and its nucleus, which is approximately 10^5 or five orders of magnitude.

Explanation

The concept of stating ratios of quantities as differences of orders of magnitude is exemplified by the significant difference between the diameter of the hydrogen atom and its nucleus, which is approximately 10^5 or five orders of magnitude.

3. State the fundamental units in the SI system.

Gram, liter, minute, volt, joule, celsius

Kilogram, kilometer, hour, ampere, mole, celsius

Gram, meter, minute, ampere, mole, kelvin

Students need to know the following: kilogram,meter, second, ampere, mole and kelvin.

The SI system includes the fundamental units: kilogram (mass), meter (length), second (time), ampere (electric current), mole (amount of substance), and kelvin (temperature). The incorrect answers provided do not match the correct fundamental units of the SI system.

Explanation

The SI system includes the fundamental units: kilogram (mass), meter (length), second (time), ampere (electric current), mole (amount of substance), and kelvin (temperature). The incorrect answers provided do not match the correct fundamental units of the SI system.

4. Convert between different units of quantities.

Converting between grams and liters.

Converting between meters and seconds.

For example, J and kW h, J and eV, year and second,and between other systems and SI.

Converting between Celsius and Fahrenheit.

The correct answer provided covers converting between various units such as joules and kilowatt-hours, joules and electronvolts, years and seconds, and other systems with the International System of Units (SI). The incorrect answers do not relate to the broad range of conversions mentioned in the question.

Explanation

The correct answer provided covers converting between various units such as joules and kilowatt-hours, joules and electronvolts, years and seconds, and other systems with the International System of Units (SI). The incorrect answers do not relate to the broad range of conversions mentioned in the question.

5. State values in scientific notation and in multiples of units with appropriate prefixes.

For example, use nanoseconds or gigajoules.

For instance, utilize microseconds or megawatts.

Such as picoseconds or kilowatt-hours.

Like femtoseconds or terawatts.

The correct answer is providing examples of values in scientific notation and multiples of units with appropriate prefixes. The incorrect answers also suggest similar examples with different units and prefixes to choose from.

Explanation

The correct answer is providing examples of values in scientific notation and multiples of units with appropriate prefixes. The incorrect answers also suggest similar examples with different units and prefixes to choose from.

6. Distinguish between precision and accuracy.

Accuracy - The number of decimal places in a measurement. Precision - The consistency of repeated measurements.

Accuracy- Anindication of how close a measurement is to the accepted value (a measure of correctness).
Precision - An indication ofthe agreement among a number of measurements made in the same way (a measure ofexactness).

Accuracy - The exactness of a measurement. Precision - The confidence level associated with a measurement.

Accuracy - The reproducibility of a measurement. Precision - How well a measurement represents an overall trend.

Accuracy refers to how close a measurement is to the true or accepted value, while precision refers to the consistency or reproducibility of the measurements made.

Explanation

Accuracy refers to how close a measurement is to the true or accepted value, while precision refers to the consistency or reproducibility of the measurements made.

7. 1.2.8: Explain how the effects of random errors may be reduced.

Ignoring the errors.

Using different equipment.

Changing the experimental procedure.

Multiple trials. Students should be aware that systematic errors arenot reduced by repeating readings.

Systematic errors are not reduced by repeating readings. The best way to reduce random errors is by conducting multiple trials to average out the effects of the errors.

Explanation

Systematic errors are not reduced by repeating readings. The best way to reduce random errors is by conducting multiple trials to average out the effects of the errors.

8. Define displacement, velocity, speed and acceleration.

1. Displacement (s) - distance traveled from afixed point in a particular direction 2. *Velocity (u,v) - rate of change of displacement 3. *Speed (u,v) - rateof change of distance 4. *Acceleration (a) - rateof change of velocity

2. Speed (u,v) - distance divided by time

1. Velocity (u,v) - distance traveled over time

3. Distance (d) - rate of change of displacement

Velocity is the rate of change of displacement (not distance), and Speed is the rate of change of distance (not distance divided by time). Displacement is different from distance as it specifically refers to the distance traveled from a fixed point in a particular direction.

Explanation

Velocity is the rate of change of displacement (not distance), and Speed is the rate of change of distance (not distance divided by time). Displacement is different from distance as it specifically refers to the distance traveled from a fixed point in a particular direction.

9. Explain the difference between instantaneous and average values of speed, velocity and acceleration.

Instantaneous: one point in time, infinitesimally small
Average: Over a period of time

Average values are always higher than instantaneous values.

One is calculated using calculus, the other using algebra.

Instantaneous values are only applicable in theory, not in practice.

Instantaneous values represent a specific moment in time, while average values are calculated over a period of time. The incorrect answers provided do not accurately capture the distinction between instantaneous and average values of speed, velocity, and acceleration.

Explanation

Instantaneous values represent a specific moment in time, while average values are calculated over a period of time. The incorrect answers provided do not accurately capture the distinction between instantaneous and average values of speed, velocity, and acceleration.

10. Under what conditions can the equations for uniformly accelerated motion be applied?

Acceleration is decreasing over time.

Acceleration is constant, not changing.

The object is stationary.

Acceleration is negative.

The equations for uniformly accelerated motion can only be applied when the acceleration is constant, meaning it does not change its value over time. If the object is stationary, has decreasing acceleration, or has negative acceleration, the equations would not be valid.

Explanation

The equations for uniformly accelerated motion can only be applied when the acceleration is constant, meaning it does not change its value over time. If the object is stationary, has decreasing acceleration, or has negative acceleration, the equations would not be valid.

11. Describe the effects of air resistance on falling objects.

Air resistance causes falling objects to accelerate at a faster rate.

Air resistance has no effect on falling objects.

Only qualitative descriptions are expected. Studentsshould understand what is meant by terminalspeed. The constant velocity that theobject attains is called the terminal velocity, will not fall any faster. Air resistance imposes a drag force due to interaction of falling object with air molecules.

Air resistance causes falling objects to fall in a straight vertical path with no deviation.

When an object falls, air resistance slows it down, opposing the force of gravity. The terminal velocity is reached when the drag force equals the gravitational force, resulting in a constant speed. This is why the object does not accelerate further.

Explanation

When an object falls, air resistance slows it down, opposing the force of gravity. The terminal velocity is reached when the drag force equals the gravitational force, resulting in a constant speed. This is why the object does not accelerate further.

12. Calculate the weight of a body using the expression W = mg.

W = g/m.

W = m + g.

W = m/g.

W=mg

The correct formula for calculating weight using mass (m) and acceleration due to gravity (g) is W = mg.

Explanation

The correct formula for calculating weight using mass (m) and acceleration due to gravity (g) is W = mg.

13. Identify the forces acting on an object and draw free-body diagrams representing the forces acting.

Only some forces need to be represented in free-body diagrams.

Each force should be labelled by name or givena commonly accepted symbol.

Free-body diagrams are not necessary to identify forces.

Forces do not need to be labelled in free-body diagrams.

When identifying forces and drawing free-body diagrams, it is important to label each force to have a clear understanding of all the forces acting on the object. This labeling helps in accurately analyzing and solving problems related to force interactions.

Explanation

When identifying forces and drawing free-body diagrams, it is important to label each force to have a clear understanding of all the forces acting on the object. This labeling helps in accurately analyzing and solving problems related to force interactions.

14. State the condition for translational equilibrium.

Net force is non-zero, resulting in acceleration.

There is a balance of forces but still acceleration is present.

Velocity is constantly changing despite balanced forces.

Net force is zero, hence acceleration is 0. Constant velocity.

Translational equilibrium occurs when the net force acting on an object is zero, resulting in zero acceleration and the object maintaining a constant velocity.

Explanation

Translational equilibrium occurs when the net force acting on an object is zero, resulting in zero acceleration and the object maintaining a constant velocity.

15. Define linear momentum and impulse.

1. Linear Momentum (p) - productof mass and velocity 2. *Impulse (J) - changein momentum

1. Linear Momentum (p) - the rate of change of momentum; 2. Impulse (J) - the change in position over time

1. Linear Momentum (p) - the energy due to motion; 2. Impulse (J) - the pressure exerted on an object

1. Linear Momentum (p) - the force acting on an object; 2. Impulse (J) - the gravitational pull on an object

16. State the law of conservation of linear momentum.

Linear momentum is always conserved when external forces are applied.

Linear momentum is inversely proportional to velocity.

Law of Conservation of Linear Momentum - The total momentum of an isolated system (noexternal forces) remains constant.

The total momentum of a system can change randomly.

The correct answer explains that the total momentum of an isolated system remains constant. The incorrect answers provide false statements regarding linear momentum conservation.

Explanation

The correct answer explains that the total momentum of an isolated system remains constant. The incorrect answers provide false statements regarding linear momentum conservation.

17. Outline what is meant by work.

The amount of physical or mental effort exerted to complete a task.

The energy stored in an object due to its position or state.

The result of a machine operating to achieve a specific goal.

The product of a force on an object and thedisplacement of the object in the direction of the force.

Work in the context of physics is specifically defined as the product of force and displacement in the direction of the force. It is not just referring to effort, machine operations, or energy stored in an object.

Explanation

Work in the context of physics is specifically defined as the product of force and displacement in the direction of the force. It is not just referring to effort, machine operations, or energy stored in an object.

18. List different forms of energy and describe examples of the transformation of energy from one form to another.

Light, magnetic, gravitational, solar

Thermal, chemical, nuclear, electrical, (see topic 8 for transformations)

Wind, geothermal, elastic, radiant

Potential, kinetic, mechanical, sound

This question tests understanding of various forms of energy and their inter-conversions.

Explanation

This question tests understanding of various forms of energy and their inter-conversions.