UPCAT Physics — Kinematics & Speed, Velocity, AccelerationExam Answer Templates

Marks

2

Topic

Basic Concepts

Difficulty

easy

Template Id

T1

Examiner Tip

Always mention scalar vs vector nature and include SI units for full marks

Model Answer

Speed is the rate of change of distance with respect to time. It is a scalar quantity measured in m/s. Velocity is the rate of change of displacement with respect to time in a specific direction. It is a vector quantity measured in m/s.

Question Type

short_answer

Answer Structure

• Line 1: Define speed with units [1 mark]
• Line 2: Define velocity with direction and units [1 mark]

Scoring Breakdown

Common Mark Deductions

• Missing units
• Not mentioning direction for velocity
• Confusing speed with velocity

Key Phrases To Include

• rate of change
• scalar quantity
• vector quantity
• direction
• m/s

Marks

3

Topic

Speed Calculations

Difficulty

medium

Template Id

T2

Examiner Tip

Always convert to SI units first and show the conversion clearly

Model Answer

Given: Distance = 120 km = 120,000 m Time = 2 hours = 7200 s Find: Average speed Solution: Average speed = Distance/Time Average speed = 120,000 m / 7200 s Average speed = 16.67 m/s Therefore, the average speed is 16.67 m/s.

Question Type

numerical

Answer Structure

• Given values with unit conversions [1 mark]
• Formula and substitution [1 mark]
• Calculation and final answer with units [1 mark]

Scoring Breakdown

Common Mark Deductions

• Forgetting unit conversions
• Missing calculation steps
• Wrong units in final answer

Key Phrases To Include

• Given
• Find
• Solution
• unit conversion
• m/s

Marks

1

Topic

Acceleration

Difficulty

easy

Template Id

T3

Examiner Tip

Include both the definition and SI unit for complete answer

Model Answer

Acceleration is the rate of change of velocity with respect to time. SI unit: m/s²

Question Type

very_short_answer

Answer Structure

• Complete definition with SI unit [1 mark]

Scoring Breakdown

Common Mark Deductions

• Incomplete definition
• Wrong or missing units

Key Phrases To Include

• rate of change of velocity
• time
• m/s²

Marks

5

Topic

Free Fall Motion

Difficulty

medium

Template Id

T4

Examiner Tip

Establish clear sign convention at the beginning and interpret the final answer's sign

Model Answer

Given: Initial velocity (u) = +20 m/s (upward, taking upward as positive) Time (t) = 3 s Acceleration due to gravity (g) = -10 m/s² (downward) Find: Final velocity (v) Solution: Using the equation: v = u + at Here, a = -g = -10 m/s² (acceleration is opposite to initial velocity) Substituting values: v = 20 + (-10)(3) v = 20 - 30 v = -10 m/s Therefore, the velocity after 3 seconds is 10 m/s downward.

Question Type

numerical

Answer Structure

• Given values with proper sign convention [1 mark]
• Identification of appropriate kinematic equation [1 mark]
• Correct substitution with signs [1 mark]
• Accurate calculation [1 mark]
• Final answer with direction interpretation [1 mark]

Scoring Breakdown

Common Mark Deductions

• Ignoring sign convention
• Wrong equation selection
• Misinterpreting negative result

Key Phrases To Include

• sign convention
• kinematic equation
• upward positive
• downward negative

Marks

3

Topic

Basic Concepts

Difficulty

medium

Template Id

T5

Examiner Tip

Use the same scenario to show both distance and displacement for clarity

Model Answer

Distance: - Total path length traveled - Scalar quantity (no direction) - Always positive - Example: A person walks 3 km east, then 4 km west. Distance = 7 km Displacement: - Shortest straight-line distance between initial and final positions - Vector quantity (has direction) - Can be positive, negative, or zero - Example: Same person's displacement = 3 km - 4 km = -1 km (1 km west)

Question Type

short_answer

Answer Structure

• Definition and nature of distance [1 mark]
• Definition and nature of displacement [1 mark]
• Appropriate example showing the difference [1 mark]

Scoring Breakdown

Common Mark Deductions

• Not mentioning scalar/vector nature
• Poor or missing examples
• Confusing the two concepts

Key Phrases To Include

• path length
• straight-line distance
• scalar
• vector
• direction

Marks

2

Topic

Newton's Laws

Difficulty

easy

Template Id

T6

Examiner Tip

Include both conditions: object at rest AND object in motion

Model Answer

Newton's first law of motion (Law of Inertia) states that: An object at rest will remain at rest, and an object in motion will remain in motion at constant velocity, unless acted upon by an external net force.

Question Type

short_answer

Answer Structure

• Name of the law [0.5 mark]
• Complete statement of the law [1.5 marks]

Scoring Breakdown

Common Mark Deductions

• Incomplete statement
• Missing reference to external force
• Confusing with other laws

Key Phrases To Include

• law of inertia
• at rest
• constant velocity
• external net force

Marks

3

Topic

Acceleration Calculations

Difficulty

medium

Template Id

T7

Examiner Tip

Remember the conversion: 1 km/h = 5/18 m/s for quick calculation

Model Answer

Given: Initial velocity (u) = 0 m/s (from rest) Final velocity (v) = 60 km/h = 60 × (1000/3600) = 16.67 m/s Time (t) = 10 s Find: Acceleration (a) Solution: Using a = (v - u)/t a = (16.67 - 0)/10 a = 16.67/10 a = 1.67 m/s² Therefore, the acceleration is 1.67 m/s².

Question Type

numerical

Answer Structure

• Given values with unit conversion [1 mark]
• Formula application and substitution [1 mark]
• Calculation and final answer [1 mark]

Scoring Breakdown

Common Mark Deductions

• Incorrect unit conversion
• Using wrong conversion factor
• Missing units

Key Phrases To Include

• from rest
• unit conversion
• km/h to m/s
• acceleration formula

Marks

2

Topic

Types of Motion

Difficulty

easy

Template Id

T8

Examiner Tip

Mention both speed AND direction when discussing velocity

Model Answer

Uniform motion: An object moves with constant velocity (same speed and direction). The acceleration is zero. Example: A car moving at 50 km/h in a straight line. Non-uniform motion: An object moves with changing velocity (changing speed and/or direction). The acceleration is non-zero. Example: A car speeding up or slowing down.

Question Type

short_answer

Answer Structure

• Definition of uniform motion with example [1 mark]
• Definition of non-uniform motion with example [1 mark]

Scoring Breakdown

Common Mark Deductions

• Confusing speed with velocity
• Not mentioning acceleration
• Poor examples

Key Phrases To Include

• constant velocity
• changing velocity
• zero acceleration
• non-zero acceleration

Marks

5

Topic

Free Fall and Graphs

Difficulty

hard

Template Id

T9

Examiner Tip

Always use a ruler for graphs and label axes clearly with units

Model Answer

[Draw a straight line graph starting from origin with positive slope] Graph Features: 1. The graph is a straight line starting from the origin (if dropped from rest) 2. The slope is positive and constant, equal to acceleration due to gravity (g = 9.8 m/s²) 3. Velocity increases uniformly with time 4. The area under the graph gives the displacement 5. The slope represents acceleration, which is constant in free fall

Question Type

diagram_based

Answer Structure

• Neat, labeled diagram [2 marks]
• Explanation of straight line nature [1 mark]
• Mention of slope representing acceleration [1 mark]
• Additional features like area under curve [1 mark]

Scoring Breakdown

Common Mark Deductions

• Poorly drawn graph
• Missing labels
• Incorrect explanation of features

Key Phrases To Include

• straight line
• constant slope
• acceleration due to gravity
• area under curve

Marks

5

Topic

Equations of Motion

Difficulty

medium

Template Id

T10

Examiner Tip

Always state when each equation is most useful - this shows understanding

Model Answer

The three equations of motion for uniformly accelerated motion are: 1. v = u + at Used when: Final velocity, initial velocity, acceleration, and time are involved 2. s = ut + ½at² Used when: Displacement, initial velocity, acceleration, and time are involved (final velocity not required) 3. v² = u² + 2as Used when: Final velocity, initial velocity, acceleration, and displacement are involved (time not required) Where: v = final velocity, u = initial velocity, a = acceleration, t = time, s = displacement These equations apply only to motion with constant acceleration.

Question Type

long_answer

Answer Structure

• First equation with application [1 mark]
• Second equation with application [1 mark]
• Third equation with application [1 mark]
• Definition of variables [1 mark]
• Condition for applicability [1 mark]

Scoring Breakdown

Common Mark Deductions

• Wrong equations
• Missing applications
• Not defining variables
• Forgetting conditions

Key Phrases To Include

• uniformly accelerated motion
• constant acceleration
• variables defined

Marks

3

Topic

Velocity Concepts

Difficulty

medium

Template Id

T11

Examiner Tip

Emphasize the concept of 'limiting value' for full understanding

Model Answer

Instantaneous velocity is the velocity of an object at a specific instant of time. It is the limiting value of average velocity as the time interval approaches zero. Differences: - Average velocity = total displacement/total time (over a time interval) - Instantaneous velocity = velocity at a particular moment - Average velocity may not represent the actual velocity at any instant - Instantaneous velocity gives the exact velocity at that moment

Question Type

short_answer

Answer Structure

• Definition of instantaneous velocity [1 mark]
• Comparison with average velocity [1 mark]
• Key differences explained [1 mark]

Scoring Breakdown

Common Mark Deductions

• Vague definitions
• Not explaining the limiting concept
• Missing key differences

Key Phrases To Include

• specific instant
• limiting value
• time interval approaches zero
• particular moment

Marks

3

Topic

Free Fall Calculations

Difficulty

hard

Template Id

T12

Examiner Tip

Remember the specific formula for distance in nth second, not total distance

Model Answer

Given: Acceleration due to gravity (g) = 10 m/s² Initial velocity (u) = 0 (starts from rest) Find: Distance traveled in 3rd second Solution: Distance in nth second = u + (g/2)(2n-1) For 3rd second, n = 3 Distance in 3rd second = 0 + (10/2)(2×3-1) = 5 × (6-1) = 5 × 5 = 25 m Therefore, distance traveled in 3rd second is 25 m.

Question Type

numerical

Answer Structure

• Given values and appropriate formula [1 mark]
• Substitution with n = 3 [1 mark]
• Calculation and final answer [1 mark]

Scoring Breakdown

Common Mark Deductions

• Using wrong formula
• Calculating total distance instead of distance in specific second
• Calculation errors

Key Phrases To Include

• nth second formula
• freely falling
• starts from rest

Marks

2

Topic

Newton's First Law

Difficulty

easy

Template Id

T13

Examiner Tip

Give examples that clearly show resistance to change in motion state

Model Answer

Inertia is the property of matter by which it resists any change in its state of rest or uniform motion. Examples: 1. Passengers jerk backward when a bus starts suddenly (inertia of rest) 2. Passengers jerk forward when a bus stops suddenly (inertia of motion)

Question Type

short_answer

Answer Structure

• Complete definition of inertia [1 mark]
• Two appropriate examples [1 mark]

Scoring Breakdown

Common Mark Deductions

• Incomplete definition
• Poor examples
• Not mentioning both rest and motion

Key Phrases To Include

• property of matter
• resists change
• state of rest or motion

Marks

5

Topic

Free Fall Problems

Difficulty

medium

Template Id

T14

Examiner Tip

Solve systematically - find time first, then use it to find velocity

Model Answer

Given: Height (h) = 45 m Initial velocity (u) = 0 (dropped from rest) Acceleration (g) = 10 m/s² Find: (i) Time taken (t), (ii) Final velocity (v) Solution: (i) For time taken: Using s = ut + ½gt² 45 = 0×t + ½×10×t² 45 = 5t² t² = 9 t = 3 s (ii) For final velocity: Using v = u + gt v = 0 + 10×3 v = 30 m/s Therefore, time taken = 3 s and final velocity = 30 m/s

Question Type

numerical

Answer Structure

• Given values clearly stated [1 mark]
• Appropriate equation for time calculation [1 mark]
• Correct calculation of time [1 mark]
• Appropriate equation for velocity calculation [1 mark]
• Correct final answers with units [1 mark]

Scoring Breakdown

Common Mark Deductions

• Wrong equation selection
• Calculation errors
• Missing units
• Not showing both parts

Key Phrases To Include

• dropped from rest
• kinematic equations
• free fall

Marks

3

Topic

Terminal Velocity

Difficulty

hard

Template Id

T15

Examiner Tip

Emphasize the balance of forces and resulting constant velocity

Model Answer

Terminal velocity is the maximum constant velocity reached by a falling object when the force of air resistance equals the gravitational force. Explanation: - Initially, object accelerates due to gravity - As velocity increases, air resistance increases - When air resistance = weight, net force becomes zero - Object then moves with constant velocity (terminal velocity) - No further acceleration occurs

Question Type

short_answer

Answer Structure

• Definition of terminal velocity [1 mark]
• Explanation of force balance [1 mark]
• Description of the process [1 mark]

Scoring Breakdown

Common Mark Deductions

• Not mentioning force balance
• Incomplete explanation
• Confusing with free fall

Key Phrases To Include

• constant velocity
• air resistance
• gravitational force
• net force zero