How is the average value calculated?
The average value is calculated by dividing the sum of all values by the number of values:
Average = (Sum of all values) / (Number of values)
What is speed?
Speed is the distance traveled per unit time.
Speed = Distance / Time
What is velocity?
Velocity is the displacement per unit time in a specific direction.
Velocity = Displacement / Time
It is a vector quantity (has both magnitude and direction).
What is acceleration?
Acceleration is the rate of change of velocity per unit time.
Acceleration = (Final velocity - Initial velocity) / Time
It is a vector quantity.
How do you calculate average speed?
Average speed = Total distance traveled / Total time taken
What is deceleration?
Deceleration is the negative acceleration (a decrease in velocity) over time. It occurs when the velocity of an object is reducing.
Deceleration = (Initial velocity - Final velocity) / Time
What is the acceleration of freefall near the Earth’s surface?
The acceleration of freefall (g) near the Earth’s surface is approximately 9.8 m/s².
This value is nearly constant for objects in freefall near Earth’s surface.
What happens to the speed of a falling object without air resistance?
Without air resistance, an object falls with the same acceleration (9.8 m/s²).
Its speed increases at a steady rate as it falls, and its velocity continues to increase until it hits the ground.
What happens to a falling object with air resistance?
In a uniform gravitational field, objects experience both weight and friction (air resistance).
As the speed of the falling object increases, the force of air resistance also increases, reducing the net force acting on the object. Eventually, the object reaches terminal velocity where the forces of weight and air resistance are balanced.
What is terminal velocity?
Initially, the upward air resistance isn’t high, meaning there is unbalanced forces as air resistance increases. It’s enough to balance downward force. When air resistance equals weight of object, forces are balanced. The object now falls at constant speed called terminal velocity.
What is terminal velocity?
Terminal velocity is the constant speed that a freely falling object eventually reaches when the force of air resistance equals the weight of the object. At this point, the object stops accelerating and continues to fall at a steady speed.
How does an object reach terminal velocity?
Initially, upward air resistance is low, so there is an unbalanced force with more downward force. As the object falls, air resistance increases. Eventually, it increases enough to balance the downward force (weight). When air resistance equals weight, the forces become balanced, and the object falls at a constant speed called terminal velocity.
Can an object have constant speed but changing velocity?
Yes. Example: A car driving in a circle. Speed is constant, but direction is changing, so velocity is changing.
What is the acceleration of a stone thrown upwards at the very top of its path?
9.8 m/s² downwards. (Even though velocity is momentarily zero, gravity is still acting on it).
What is the difference between Speed and Velocity?
Speed has magnitude only (Scalar). Velocity has magnitude and direction (Vector).
What is the equation for Acceleration (a)?
a = (v - u) / t (where v=final velocity, u=initial velocity).
What is the unit for Acceleration?
Metres per second squared (m/s²).
What does the gradient of a Distance-Time graph represent?
Speed.
What does a horizontal (flat) line on a Distance-Time graph mean?
The object is stationary (at rest).
What does the gradient of a Speed-Time graph represent?
Acceleration.
What does the area under a Speed-Time graph represent?
Distance travelled.
What is the approximate value of acceleration of freefall (g) near Earth?
9.8 m/s² (often rounded to 10 m/s² in exams).
Describe the motion of an object falling in a vacuum (no air resistance).
It falls with constant acceleration (g) because the only force is weight.
What forces act on a falling object in air?
Weight (downwards) and Air Resistance/Drag (upwards).
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Motion, Forces and Energy1
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1.1 Physical Quantities and Measurement Techniques42
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1.2 Motion28
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1.3 Mass and Weight20
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1.4 Density20
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1.5 Forces37
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1.6 Momentum19
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1.7 Energy, work and Power69
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1.8 Pressure20
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2.1 Kinetic Particle Model of Matter41
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2.2 Thermal Properties and Temperature40
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2.3 Transfer of thermal energy50
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3.1 General Properties of Waves41
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3.2 Light36
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3.3 Electromagnetic Spectrum37
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3.4 Sound42
