Measurement of Time and Motion – Formula & Equation Sheet
Essential formulas and equations from Curiosity, tailored for Class 7 in Science.
This one-pager compiles key formulas and equations from the Measurement of Time and Motion chapter of Curiosity. Ideal for exam prep, quick reference, and solving time-bound numerical problems accurately.
Key concepts & formulas
Essential formulas, key terms, and important concepts for quick reference and revision.
Formulas
Speed = Distance / Time
Speed (m/s) is the rate at which an object covers distance (meters) over time (seconds). Useful for calculating how fast an object moves.
Distance = Speed × Time
Distance (meters) can be calculated by multiplying speed (m/s) by time (seconds). This formula is essential for problems involving travel.
Time = Distance / Speed
Time (seconds) is derived by dividing distance (meters) by speed (m/s). Useful to assess how long a journey will take.
Time Period (T) = 2π√(L/g)
T is the time period (seconds) of a simple pendulum. L is the length (meters) of the pendulum and g is the acceleration due to gravity (≈ 9.81 m/s²). Indicates how long it takes for one complete oscillation.
1 minute = 60 seconds
This conversion factor indicates that a minute is made up of 60 seconds, critical for time calculations.
1 hour = 60 minutes
This conversion shows how hours relate to minutes, essential for understanding larger time intervals.
Distance = Velocity × Time
This formula is used when dealing with constant velocity (meters/second) to find distance traveled over time.
Average Speed = Total Distance / Total Time
Average speed (m/s) is calculated by dividing total distance (meters) by total time (seconds). Useful in multi-segment journeys.
Acceleration (a) = (Final Velocity - Initial Velocity) / Time
Acceleration (m/s²) measures the rate of change of velocity (meters/second) over time (seconds). Important for understanding motion changes.
Frequency (f) = 1 / Time Period (T)
Frequency (Hertz) indicates how often an event occurs in one second, inversely related to the time period.
Equations
Ohm’s Law: V = IR
V is voltage (volts), I is current (amperes), and R is resistance (ohms). It defines the relationship between current and voltage in a conductor.
Work Done (W) = Force (F) × Displacement (d) × cos(θ)
W is work done (joules), F is force (newtons), d is displacement (meters), and θ is the angle between the force and displacement direction. Important in physics for energy transfer.
Kinetic Energy (KE) = 1/2 mv²
KE is kinetic energy (joules), m is mass (kg), and v is velocity (m/s). This equation quantifies energy due to motion.
Potential Energy (PE) = mgh
PE is potential energy (joules), m is mass (kg), g is acceleration due to gravity (≈ 9.81 m/s²), and h is height above ground (meters). Crucial for understanding stored energy.
Impulse = Change in Momentum = Ft
Impulse (N·s) relates force (newtons) applied over time (seconds) to change in momentum (kg·m/s), important in collision physics.
Momentum (p) = mv
p is momentum (kg·m/s), m is mass (kg), and v is velocity (m/s). Essential for understanding motion and collisions.
Friction (f) = μN
f is friction (newtons), μ is the coefficient of friction (dimensionless), and N is the normal force (newtons). Important in analyzing motion.
Gravitational Force (F) = G(m1m2/r²)
F is gravitational force (newtons), G is the gravitational constant (≈ 6.674×10⁻¹¹ N·m²/kg²), m1 and m2 are masses (kg), and r is distance (meters) between centers of mass. Fundamental in understanding gravitation.
Power (P) = Work Done / Time
P is power (watts), work done is in joules, and time is in seconds. Indicates the rate of doing work.
Density (ρ) = Mass / Volume
ρ is density (kg/m³), mass is in kilograms, and volume is in cubic meters. Important in material science.
